upgrade help needed

morning folks. specs are as follows on current set-up.
intel core 2 duo e8400 3ghz 6mb
intel c2d p43tf ddr2 800
ddr2-800 2gb pc6400 ram
seagate 160g sata II 8mb hd
evga edgeforce 9600gt 512mb ddr3 pcie
sagita midcase black 500w
xp home
19" acer lcd
believe that’s all the specs.
would like to go with 260-216 card. also better psu. also a 24" lcd under 500 dollars. only serious games are microsoft flight sim gold edition and grid. thanks for any help. frank. have a great weekend.

thanks for all the helpful replies. frank.

What is a 260-216 card?

This is a good 610W PSU:Newegg.com - PC Power & Cooling S61EPS 610W Continuous @ 40°C EPS12V SLI Certified CrossFire Ready 80 PLUS Certified Active PFC Power Supply - Power Supplies

think he means Nvidia GTX 260. 216 cores not the 192 cores.
If he does I would recommened this card it’s a really good performer.