If you do a search (no this isn't a search, noob post) for "party pig" you'll find TONS of reviews and experiences to help you with your decision.
Also, check out Tap-a-draft as well. That's the one I went with and it works great too.
That said, if you think you'll upgrade to a real kegging system, just do that. Most folks who get a party pig or a TAD system "for now", decide to move up to kegging really quickly after and wish they'd just spent the money towards kegging. I got the TAD because I didn't have any room to keg and it was a great halfway measure for me. Plus, you can get extra TAD bottles fairly cheap (in some areas you can buy 3-liter pop bottles that also fit the TAD system) so you can expand your storage without too much more outlay of cash.