I program Crestron controlled systems for a living and can't speak about everything, but can talk about a few things.
1. Yamaha receivers are simply the best I have ever worked with! About 2 years ago Yamaha completely re-thought their lineup and engineering and now EVERY aspect of your receiver has disrete codes. Zone 1 On, Zone 1 Off, Zone 2 On, Zone 2 Off, Zone 3 On... etc., etc. Separate volume controls for every zone... It is all through discrete IR for each zone. But, you only need ONE IR emitter! The IR codes are just different for every zone you use. Freakin' fantastic. Also, they have RS-232 ports which work better than any other receiver I have used.
Marantz receivers didn't work at all, Integra was flakey. Sony just doesn't support thier product, but I am hearing better things about them. Denon receivers tend to work pretty well also, though I have only used one, I have heard good things about them.
2. DVD players aren't that big of a deal. Mostly you want 'on' and 'off' functions. I personally use a Sony DVP-NS725p which gives discrete control at a reasonable price. Though, I think all Sony DVD players include discrete on and off which makes them easy to use.
3. Mitsubishi or JVC VCRs should give you discrete on and off as well.
DVD & VCRs with RS-232 end up costing a lot more than they are worth in my opinion, and it is better to go with IR. If you don't want IR on the front of your unit, you can bury it inside, or find a unit with rear IR input. I personally buried my IR emitters inside my units. It took about an hour, but it only cost about 100 bucks for the DVD player.
