Welcome to AVS! Anyway, about your question, NefariousOne gave a good suggestion - those two threads are excellent threads to read. Your budget is a bit low for me to start recommending that you piece your system together, especially since you want a receiver that will have the features to last for a while without becoming outdated. I would personally recommend the Onkyo 908 HTIB. It sounds as if you at some point would be upgrading your speakers, and the receiver that comes with it (Onkyo 605) is an excellent receiver brimming with features. For the time being, the speakers in the 908 aren't terrible (though you'll certainly notice a big difference when you upgrade to something else), and again, the receiver should have most everything you'll need for quite some time.
I'd personally recommend the Onkyo 908 over the Samsung 720. The receiver for the Onkyo is a higher quality receiver, and will definitely be able to handle bigger speakers (should you choose to upgrade, of course) much better than the Samsung. I'd ignore the slightly better price of the Samsung - the Onkyo 908 is still in your price range ($669 at amazon right now) and should be a better performer, both out of the box and once you upgrade the speakers. Just my two cents. Be sure to read up plenty, though. Make informed decisions - there's a lot of good advice on AVS, and some not-so-good advice, but make sure you end up getting what suits YOU best, not what I or anyone else says is best. Good luck!