Looking for amp advice (punk, rock & reggae edition)

Let me run you through the math and explain why a 30 watt class A amp would destroy your hearing with those speakers. 

Here's how the math breaks down. 2.83V through an 8 ohm load draws .353 amp and 1 watt. If the speaker only ever presented an 8 ohm load with no reactance, calculating by the watt would work. But we know that speaker doesn't do that. We can calculate for that though. 

Let's round the low point to 4 ohms for simplicity. Now we put the 2.83V through it at it's low point frequency. At a meter it's still making 92dB but because of the halved impedance it's drawing twice the current, .706 amp. That's 2 watts. The speaker doesn't respond flatly to power (watts) input. It responds flatly to voltage. That's why the amp needs to deliver current. If the amp doesn't deliver the current to support the voltage, the voltage will sag. 

Now let's figure the distance. For each doubling of distance you square the power. So, at 8 ohm at 6 feet you need 4 watts. At 12 feet you need 16 watts. Halve the impedance and you need 32 watts to get your 92 dB. But, you're not listening in half sphere free space, nor to just one speaker. Each of those factors buys you about 3dB of reinforcement so now you're 32 watts is getting you more like 98dB. That's very, very loud. Hearing damaging loud. And that's assuming the music material is that loud consistently, which virtually no real music actually is. 

A good class A 30 watt push-pull amp usually has an envelope of twice that power. I depend on that with my F5. It will belt out 64 watts into that 2.8 ohm load without a hiccup. And if I do happen to drive it even harder, the amp just transitions to class AB and keeps driving current. That nominally rated 32 watt amp has more than enough power to damage my hearing in minutes sitting 12 feet away. It's not going to do it at 110Hz, but nobody listens to test tones. That amp effortlessly vibrates my chair and rattles the walls. 

I hope that math makes some sense.

It does. Yes.

Awesome!

All of that said, class D and AB amps have nowhere near the headroom most class A amps have. A class AB or D amp's rating is usually a pretty hard limit produced by the limit of the power supply to drive voltage, current, or both. The reason your Marantz peters out at 45 watts is that's the limit of the voltage it can reliably push into 8 ohm.. It reaches up 70 watts at 4 ohm because the power supply has some reserve capability, but not much. The power supply in my F5 will swing 150 watts reliably before it melts the outputs or pops the fuse. You rarely see class AB or D amps built like that. And there are guys building out Aleph J's and F5's with dual power supplies and making real monsters out of them for less than you're looking to spend. 

So I need class A with good voltage delivery and not tons of wattage.  Something like the F5 Yes?

I'm not going to say you NEED good class A amp. I highly recommend them though. I built my amp and tweaked that thing for months until it sounded just the way I wanted. I don't have the best speakers on Earth, nor the best amp, but they're probably better matched to each other than most speakers and and amps out there and that makes up for a lot.