i have built my own, and bought pre made ones, its much less hassle to buy the pre made ones, i have both a 2.5 80GB lacie mobile drive, and several 250 , 500 , desktop drives from them. most bus powerd drives are 2.5 in with spindle speeds of 4200 to 5400rpm to my knowledge there are only two bus powerd hdd.s on the market with 7200 rmp 2.5" drives, both made by lacie, one is the rugged drive, and the other is the little big disc, however thjis one needs fw800 for the powerd bus