i have a mac mini, and an imac G4, if you want to combine them, be up for the challange, my iMac has a few mods though, i removed the internal display, and added extra cooling, put the sleep light on the front next to the drive(Drilling required) and put the mic in one of the top holes, and run the computer connected to an external display, the iMac guts are hard to remove, and are designed to accomadate imac parts, you couls use the drive cage with a sata 5.25" optical drive Drive and a standard 3.5" hard drive, with some cable manipulation, but there is no way you could hook the internal display to the mac mini, it uses a non-standard connector directly to the logic board, so if you want it to be headless, go agead, you might even be able to get the external power brick from the mini inside the imac casing, but ther internal display wont work at least without a lot of cutting, soldering, and shrink wrap.