Haha, well thats a first for me. I've had my name in there for a month or two now and you're the first to use it
7.1 is awesome, some could argue that not much if any movies are actually mixed in 7.1 or higher. I believe I read somewhere that movies are recorded or mixed or both in 5.1 and then any more channels than that are somewhat artificially added? I'm probably butchering that and I can't find the post I read it in, so I'll leave it that at that and say, for me building an awesome 5.1/5.2 would be my first priority since those two back channels can get added in at any time and can be inexpensive. I love bass, so getting a better subwoofer or two would come way before those back channels since I don't feel like you lose anything with 5 channels and the gain with 7 is minimal, at least to me. I would, as time and funds allow add those back channels and maybe two more later on, but only after I had a killer 5 channel rig first.
My own personal beliefs about audio are more or less centered around things I learned from guys around these parts who know a heck of a lot more than me, like Adam up there, but they have always preached, before me and now to me, speakers before electronics, speakers before electronics, speakers before electronics. This being the case, I think you should spend less on a receiver, maybe one that can do maybe 5.1, with the second zone, and invest a bit more in a better subwoofer and center.
You may or may not notice a difference between the receivers, but I have no doubt in my mind you will notice a difference in the sub and probably in the center as well.
Right now I'm kinda piecemealing my system together, building it slowly, and I can honestly say I overspent per my budget on electronics
but I got an offer I couldn't refuse and then ran into some power issues that got me a little worried so long story short I got two new toys and completely ruined my credibility for preaching speakers first
That being said, before I did all that I did put my deposit in for a pair of Philharmonic 3s, so I didn't totally jump ship.
For what you have, and where it seems you're heading, my advice would be to cut the receiver budget and go with a bigger more bad rear end sub. I can't imagine you'd regret it, but then again receivers are shiny and pretty so what do I know.