First World Problem in need of Solution

If 2-channel audio is your main priority, then your Option #1 is most likely the best solution.  There isn't going to be any HT Processor that is going to sound quite like your Luxman C-900u preamp.  You could go with your other options, but like you said, 2-channel audio is going to be severely compromised, especially if you are using the subs to "add bass octaves" to the natural bass of the Focal Sopra.  Everyone who runs a "hybrid rig" is compromising in the 5.1 HT side of things, but that's a necessary evil.
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If you did replace the amps, I would be very careful about matching.  Your Luxman amp is likely a very good match, along with amps such as Pass Labs (especially the XA series), maybe Parasound JC1 with high-bias Class A setting.

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For processors, I'm partial to Krell S1200U because of the Class A analog stages, but it is discontinued and does not support the new features, such as 4K video, HDR, Atmos, etc.  There are others, but for home theater movie excitement, probably the Krell Foundation is the best way to go.

Sorry, nekoaudio, but I disagree here.  A large power supply in the amp is very important, yes, but the sonic signature and how it reacts to signal/load is another important factor.  I have worked with several different amps (Bryston is one of them) and when you combine a very fast/clean amp like Bryston with a very warm/full amp such as Luxman/Parasound, what happens is an imbalance in sound and impact.  In that case, while the Bryston is a very high resolution amp, it will just not keep up with the Luxman/Parasound in volume/body/impact.  I have tested and experienced this personally.  The Bryston does have it place, but also in this case, I think it would be a very bad pairing with Focal speakers.  The Bryston would excel with a very warm preamp (such as Marantz) and paired with warmer type speakers (NOT Focal).  In my situation, the Bryston could not even keep up with my Emotiva XPR-1 amps, and I was testing the big 7b3 600 watt monoblocks.  I probably could have gotten the Bryston to work, but I did not want to re-work all my cabling back to gold-plated connectors and such.  The Brystons were powering left/right and the Emotiva was powering the center -- and the difference was very obvious.


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The Focals are very fast and clean speakers.  If you pair them with a high resolution amp such as Classe, the sound is not bad, but it is very apparent that the bass/midbass are somewhat thin and hollow sounding.  This pushes the emphasis to the high frequencies, which makes the speaker sound somewhat bright (bordering on harsh).  Pairing Focal with Bryston would create a very thin/bright sound with no body and impact.  The Focal definitely needs a very warm full amp because the speaker is such a fast responding speaker.

You probably want at least a couple hundred watts per channel.  The best solution would be to find more Luxman amps, but they are definitely very expensive!!  I don't know if you can find a smaller M-700u that you could run mono for the center channel.  Then another M-700u for the surrounds.  Be careful when buying these from Japan because the "Japan" models are usually wired for 100V A/C (which will not work properly in the US 120V standard).


Or you can try to put in a Pass Labs or Parasound amp.  Pass Labs does not make 3 channel amps, but Parasound has an A31.  Or use a Parasound JC1 for center and an A21 for surrounds.  The JC1 can be switched to high-bias Class A which may sound closer to the Luxman signature.  Or you could try a McIntosh 3-channel like the MC303, but the McIntosh will likely be a smoother sound than the Luxman/Pass/Parasound signatures. 

The Parasound P7 is not really a true HT Processor.  It's a 7 channel analog preamp.

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For HT Processor, I would recommend getting the highest resolution processor possible, depending on your budget.  If 4K is a requirement, maybe Krell Foundation 4K UHD.  If you don't need 4K, then maybe Krell S1200U or Classe SSP-800. 

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The Rotel RAP-1580 is like a HT AVR Receiver and it's probably a very good product.  But it is higher resolution and faster.  It may not be the best match for your Focal speakers, and would definitely sound different than the Luxman amps for left/right.  The Parasound A31 (or JC1 + A21 combo) would sound closer to the Luxman than the Rotel would.

@ricred - I think those amps are relatively close in sonic signature.  They are not extremely warm and not extremely fast, but both pretty neutral.  If you had a radical mismatch, I think you would notice more differences.
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@atownkeep - I hear you.  I don't think trying to get a AVR Receiver or Integrated would really be the answer here, as they all have definite differences.  I think it's much better to look for a set of amplifiers that would closely match your Luxman amps.  Then the choice of HT Premp/Processor is not that critical, since all channels would be somewhat matching.  Since HT movies really need excitement, I would probably recommend a very high resolution HT Processor for your scenario.  The warm Luxman/other amps would sound too dull with a warm HT Processor such as Marantz or Bryston SP3 (yes, the SP3 is really laid back).  I am totally not a fan of room correction, although many other people are.  Both the Krell Foundation 4K and Anthem (either D2v 3D or AVM60) have their own auto-eq and room correction.  They are both high resolution processors and support 4K.  The Classe Sigma SSP Mk II is also a good high resolution 4K processor, but it does not have auto eq or room correctoin.

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That is kind of why I put forth the idea of getting a Parasound amp - it is on the warmish side, but still has good slam.  The A31 is probably a great price for a solution ($3200 retail).  Other amps could be like Aragon (they have both a Iridium monoblock a 8008 stereo).  Or something like a B&K, but they are very old.  I'm sure there are other warmish sounding amps.  You could try posting that question in the "Preamp/Amp" thread as "recommend an amplifier that sounds very close to Luxman 900u and offers both a monoblock and stereo amp".  The list of manufacturers that would offer a 3-channel which also has that warm sound is very small.

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Maybe an idea would be to pick/buy your HT Processor and then try a Parasound A31 amp from Audio Advisor.  They do have a 30-day return policy, so if it's not close enough sounding, you can return it.