I've got KI and KI2 running perfect on a P4 2.8ghz, so you'll have no problems with your system. Also Area51MX is a lot of fun if you have guns. That also runs perfect on my system.
Only thing that runs a bit sluggish for me is Carnevil. The game actually plays ok frame rate wise, but the audio stutters. But I've seen video's where faster systems have the audio problem also.
Also have all the SF3 games running great.
Pretty much have any that I want, running ok.
Eventually plan on getting a Core 2 Duo for myself and making my current AMD 64 X2 4200+ my cabinet machine. Usually work it that way, I upgrade and the older machine goes to the cabinet. Only hold up is if I do I may as well put a 64 bit OS, but I have yet to find out if I can get my 2 EMS LCD Lightguns to work in a 64 bit OS. I need my Terminator 2, Lethal Enforcers and Area 51! Thus far I have not seen a driver for the guns thats 64 bit, and have not spoken to anyone that has them running on a 64 bit OS.