im running an oced amd 64 2800+ and a 6800 agp both oced (stock hs/f) and its in a 30 dollar .07 aluminium case, with a generic 500w psu, i modded a 120m fan to blow straight onto cpu/gpu and use a 80mm as an exhaust, and i run with ambient temp of 30-33c cpu temp at 32-35c and gpu temp at around 56c
basically try to get some cool air right onto the cpu