One point that hasn't been mentioned (but may be implied) is that all the speakers you buy (save, perhaps, the sub) should be timbre-matched. That is, buy speakers that are meant to be used together, speakers that have similarly-engineered and constructed tweeters, etc. Ideally, one has 7 speakers that are exactly the same.

Although they never (or rarely) show up in tests, I have Klipsch speakers and think they are great. Klipsch has a user forum that rivals the Outlaw forum. Klipsch makes both in-wall and in-ceiling speakers, but I think the advice to go with bookshelf or bigger speakers is good advice.

If you want a completely built-in look, there is a sub (I don't know the brand) that fits in between wall or floor studs.