You just left out speaker cable, RCA's, Y splitter, and three sub cables. Not to mention the added effort of stripping the wire, cutting to length, and HDMI board issues that the mid-level onkyo's so often seem to have.
I'm not saying it's a bad idea, but you're looking at probably another $50-100 in all that stuff, plus banana plugs if want those as well, and not an insignificant amount of effort.
If the OP is ok with that, then by all means we can start tossing out more recommendations along those lines.
TO THE ERLEWINE:
I think if you want a full 7.1, 5.1, or whatever system right away and you only have $800 to spend you could do a lot worse than the onkyo HTIB. The receiver isn't the best there is, but if you want all those speakers right away, then you have to sacrifice a little here and there. I will say this about the onkyo receiver, unlike many other HTIB's it's actually a real receiver and not just a weird box that simulates a receiver.
Plus it comes with everything you need, installation instructions (not a huge deal since you can come here for help, but worth noting) and everything is really easy to put together. I've set up a few HTIB's for my parents and some of their friends and they're super easy to setup as long as you can follow directions and have a bit of common sense. Not that setting up a "real" system is hard, it's just more tedious and there are a lot of small expenses that start to add up fast. Plus you end up spending a much larger portion of your budget on a receiver than you should when your budget is that low.
If you're serious about looking for something else you can read this and it'll give you some good ideas of what to look for and what you might be looking at in terms of purchasing.
2011 $1000 Recommended 5.1 System — Reviews and News from Audioholics
I have heard an onkyo HTIB and I actually really liked it. Not as much as my own setup, but for an HTIB it was pretty darn decent and I don't think anyone who is just starting out would regret getting one or be disappointed with the performance.
YMMV, but do let us know which direction you're leaning and we can go from there.
Cheers