Most of the slimline drives you purchase aftermarket have a JAE50 connector. You'll likely want to go slimline for the space savings and the lower power draw.
There is an adapter to make it standard IDE, but that's not going to allow a 7-foot run.
Your best bet is to go USB or firewire with an enclosure, although you can get a JAE50-to-IDE and then an IDE-to-USB (or firewire). IMHO, the enclosure is simpler.