I think a base fan would most easily connect to the molex connector on one of the drives. If you aren’t going to be doing much gaming, though, the 7500 will be perfectly happy without a fan. My kids did manage to cook a fanless Radeon 7500 in a Cube years ago while gaming (I think it was endless Harry Potter and the something or other) but all the same, it ran for a couple of years in intensive use by adolescents, and the identical replacement card is still going strong. Not that the latter has had such frequent or heavy use, mind.