pretty good specs. check out
www.newegg.com for your ram. always get name brand ram and not generic crap. good brands include crucial, kingston, ocz, patriot, corsair, and mushkin. the XFX 6800GT is pretty good and other good ones include BFG 6800GT, EVGA 6800GT, and even the leadtek 6800GT.
i have the PNY 6800GT and im really happy with it. not much of a software bundle but i got it for a good discount when i was working at compusa.
on your old system i think the pentium 2.4 is not that bad. pair your old system up with a good videocard like the 6800GT and you will get a boost in performance for sure. for example, im still using an athlon xp system, paired it up with a PNY 6800GT i play CS source at 95FPS. im happy already, i get no lag or choppiness during when im playing.