Yeah they will work, simply power them from the yellow wire (+12v) and any of the black wires (ground) from any or your power connectors. 90 milliamps is not very much power at all (a typical hardrive draws around 600mA from the 12v line), you'll have no problems with that. If your going to be using these for case lighting you might want to use 2 or 3 since they are only 7700mcd. You can get a single LED that bright.