I'm finishing my basement and will be finishing under the stairs. On one side of the stair framing I can fit up to a 64" door. I have no idea where to start looking for this. I'd prefer to use something that looks like a normal door vs. a cabinet door. Any suggestions?
Get a prehung door and cut it down to fit. You'll want to disassemble it, and cut 16" or so off the top of the door. Do the same to the jamb... cutting 16" off the top of the jambs. You'll have to re-mortise the top hinge. If it's a hollow core door, you'll have to glue a plug back into the top of the door to fill the void.
Using a prehung will likely make it easier for you- even though you will have to disassemble and reassemble it, it will save you a little work.
Not necessarily. You can trace the hinge with a utility knife and chisel it out too. Generally prehung doors come prebored for the door knobs. If you cut 18" off the bottom of the door, you'd need to get on your knees to reach the handle. Cutting the excess height off the top keeps the door knob at the standard height.
If you happened to find a prehung door that does not come prebored, then you could cut the excess off the bottom.