Go for the fans, you dont want to spend on a new vid card and then suddently have your whole system toast and have to plop more money than the vid card because the fans died. Ive had only a couple of fans go bad but I had advanced warning that the cpu was overheating so I had time to shut er' down and get a replacement.
Also unless you do some overnight filesharing, I reccomend you shut down your computer every night. Saves energy, almost doubles the life expectancy of the components because they are not running during the other half of the day while you are sleeping, ect. I do so on many different computers over the last decade and experienced no ills because of that, theres really no reason for the computer to be on overnight unless you are dl or doing maintinence like defrag, virus scan ect.
1993 Bonnieville SE "Old Ironsides" 211,xxx mi
Mods: Drilled 180 T-Stat, Carsound Cat, 8mm Beldin wires, NGK-TR55 Plugs, CAI with K&N RX-4750 and ghetto cardboard heatshield, Michelin Harmony tires.
---------------My Car Site---------------
1996 Bonneville SSEi "Double Trouble" 139,xxx
AC Delco 12-Disc Changer, Drilled 180* T-stat, NGK TR-55.
TBI: K&N RX-4750, Magnaflow Cat, Res, and Muffler