I have a 40gb model and i'm more than happy with it. I own a PS2, so I don't really care much for backward compatibility anyway and the other things that are gone don't affect me. The size of the hard drive might be of concern if you want to load up your system with music, pictures and downloable games but..still, you're given quite a bit to work with there.

Out of your choices for games to get, i'd go with Call of Duty 4. The single player portion of the game is great fun and the multiplayer is both rewarding and addicting.