Okay, so an AV Receiver is going to be your target. One thing to know with these is that it is best if you buy the biggest and most powerful one you can. Ignore the fact that it’s a “11 channel receiver”. I recommend buying the biggest because you will get the largest transformer and power supply section (which are important, as you probably know). That being said, even the biggest receiver will not have as good of a power supply as a nice 2-channel amplifier (such as Parasound A21 or similar).
Anthem makes some good receivers. You can get a used MRX710 on ebay for $1100-1500 range. Many love them. Anthem is probably the cleanest and fastest sounding AV receiver. However, I think the Anthem is a bit hard edged in the highs, but it will definitely be an exciting sound for movies. I would definitely suggest using gold-plated terminations on any speaker wire and even putting in a Isoclean gold-plated fuse or a Hi-Fi Tuning Supreme “Cu” copper fuse to take the edge off the highs.
Yamaha makes nice natural sounding receivers. You can get a used Yamaha RX-A3070 for $1300. New for $1500. It’s just one generation old. I have had extremely good results when adding a Furutech fuse into the Yamaha receivers. I usually recommend getting into the Yamaha advanced menu to set the speaker type to “6 ohm”. This changes the circuit in the Yamaha and performs better. With a speaker that has impedance drops down to 3-4, the receiver will sound weak in the bass/midbass/midrange area when set at the default “8 ohm” setting.
Marantz has good stuff, but it is definitely warm sounding with soft/rolled-off highs. Marantz has good body and impact. However, if your audience are not audiophiles that understand what they are hearing, they may think the Marantz sounds dull. One of the good things about Marantz is they have a fully discrete analog output stage in the preamp section. You can find the Marantz SR7011 and SR7012 receivers on ebay for $1300-$1600 new. They may work out if you put a fast Hi-Fi Tuning Supreme silver fuse in and/or use silver-plated bananas/spades on your speaker wire.
Speakers are an entirely different thing and if you ask “what’s the best speaker” you will get 18 different answers on this forum. There are many different options and it becomes a very “personal preference” thing here. That being said, here are some thoughts:
For bargain basement, Elac Debut speakers seem to be one of the best. You’re looking at $500-800 for a pair of full range tower speakers.
Klipsch Reference speakers are nice as well. In the $700-$1600 range. They do have a horn loaded tweeter, which has its own unique sound. However, the Klipsch have the added benefit of being an extremely efficient speaker (like 96db) so you won’t need to use as much power from the receiver (which means you’re not starving the receiver power supply).
If you want a higher resolution speaker, I suggest looking into the Monitor Audio Silver series. New models are getting into the expensive area. It’s $1,500 for a pair of Silver 200, and $2,000 for a pair of Silver 300. You can get a previous generation Silver 6 for $1200 a pair from Crutchfield. Parts Connexion has a pair of Silver 6 in White Gloss new-in-box for $899 a pair.