Hi jnelson - this thread might get a little more visibility if you move it up to the General A/V Discussions section, perhaps.
First of all, I would throw this out there, that if you're planning to build a dedicated Home Theater environment, I would recommend a projector/screen combo. It's difficult to suggest sizes and brands, unless you outline the room-to-be dimensions and your budget. You're going to get a much more authentic "theater" feel with a projection screen, and there are some very nice projectors on the market these days.
As for wiring - you'll have to figure out what configuration you're going to use and go with it (i.e., 5.1, 6.1, 7.1 - the latter being recommended for a larger dedicated HT). Wire gauges will vary as a function of distance from the amp and other factors, but typically you can't go wrong with either 12 or 14 gauge in most applications.
For cable brands - try Blue Jeans cable - they are an extremely respectable, high-quality brand with excellent customer service and a great reputation. You can order professional quality raw cable and terminate them yourself, or specify the exact length you need and they will come to you already terminated.
http://www.bluejeanscable.com/ As you will see, they have every type of cable you'll need to build the HT of your dreams.
Other wiring considerations - where your equipment rack will live, what signal you'll be running to the projector (if that's the route you take), and electrical wiring for both the projector and screen (if it's a motorized rollup variety, which some people employ). Again, this is all dependent on your budget and what you want out of the system, which is unclear from your original post.
I envy you though - I can't wait until I have a room I can dedicate to my own HT.
Best of luck!!