Hi, I recently bought a Hp Pavilion a6532f and I want to change the power supply to a 430-450 watt power supply to power the Sparkle Nvidia GeForce 8600. The power requirement on the box says 300w but I want to be safe. I have contacted HP for assistance on what power supply would fit in the case, and they redirected me to several resellers, but they all only had the original 250w power supply. Can most power supplies fit in any case? or do they have to fit the dimensions of the original? Cases have latches that support the battery, and I am not sure what to get. If anyone has any idea on what I should get, or knows a lot about power supplies and can give me some information, it would be great. The case is similar to the HP Pavilion 6400. Price is not a big factor, but I would like something around $60 or under. Thanks =)