Any E7000 or E8000 would do I think, probably the E7200 or E8400 are best buys (depends on overclocking or not) also the Q6600 is a good one if you want a Quad core...
As you don't need any extreme gaming rig, that card looks fine, but I think you could better get the 8800 Ultra, which would be more than enough for your needs, I think, or go for the newer series, 9600 or 9800 if you wish to spend a bit more, if not stick to the 8800 which is a fine card.
I would advise you to get a new PSU though, a Corsair
tbh, a 450W to 550W should be more than enough. (Corsair TX and HX series)
I don't know howmuch you want to spend on a new case, but I'm getting the Antec Three Hundred case, which is a cheap one but should do the trick either way, there's another case, which I forgot the name from, but I'm sure staffsMike can tell you all about that one xD