WOT - Home Theatre Questions, Anyone knowledgeable on this stuff? Options

[soloracer]

I just bought the following:

1 Pair Martin Logan ReQuest Speakers
1 Pair Martin Logan Quest Z Speakers
1 Martin Logan Logos Center Channel
1 Denon AVR-5800

I was planning on buying another pair of Martin Logans and a sub to finish things off. My question is regarding the amplifier and whether it's a good "economic" choice. I realize separates are probably better but usually are way more expensive. I've heard that the Martin Logans are brutal on amps and was wondering if the amplifier is suited for the job. The other thing was regarding all the different surround choices that are out there today. Is there a "must have" in terms of home theatre modes or digital TV modes (HDMI? THX ES?) I used to be into the home stereo scene but haven't been for 10 years and things have really changed.

[soloracer]

For a display I have a BenQ PB6100 projector projecting on a Daylite screen (80"). Works good in the basement but would definately wash out somewhere that had ambiant light coming in. I have had the projector for a couple of years and have been happy with it. There are probably some out now that are better and cheaper but for now I'm going to concentrate on the sound system. My old system is about 15 years old (Pioneer) and was one of the first surround sound systems made (5 Channel Dolby Pro-Logic). I think I paid $6000 Canadian for it back then and I figure it's more than done it's job for me. It's just time to step up to some newer, higher end gear.

I was considering going with Bryston or Krell for amplification but I couldn't resist the $1400 price tag that I got the Denon unit for. I figure to do the same thing with the separates I would be looking around $5000 (Processor, Pre-Amp, Amp). The Denon unit also does Dolby 7.1 which I believe requires 6 speakers and the sub in which case I will look at getting one more pair of Martin Logans (probably a pair of Scripts). The thought is I would put the ReQuests in front, Logos in the center, Quest Z's in the back and the Scripts at the back/center. For a sub I was looking at either a Descent or Grotto.

Where I need help is understanding all the new formats. Seems like there are several types of DVD format coming out that may or may not be compatible with the amplifier. There are also a bunch of different surround sound modes - much more than I am used to anyway. Can anyone tell me what is important to know and what is chaff?