If it's for movies only and not music it makes it a bit easier. I was going to buy a home theatre set up a few years ago but after talking to some people in the know I ended up going 2 channel as music was more important to me and you have to spend a fair wad to get a home theatre receiver that will match even a lower priced quality stereo amp.
My advice although I'm not an expert would be to put most of the budget into the speakers, and buy a lower powered but good quality HT receiver (like an entry level Denon, Marantz, NAD, Rotel, Cambridge Audio or something) and then you could always upgrade the receiver if you found it wasn't handling it. Probably need to think about the room size too, the experts should be able to tell you what you need to get the job done.
I'd still like a HT setup but in reality they are probably at their best on the blockbusters with the wicked audio soundtracks and I don't really watch that type of film much. I run my DVD and TV through my 2 channel Denon and it is amazing how much better it sounds than the crappy TV speakers. Just can't do surround. The V8 supercars sound good through it though!