The official word from CIG is that every ship can mount a Jump drive, even if it doesn't come with some stock.
The only exceptions are (obviously) ground vehicles, and snubs (Dragonfly, Merlin/Archimedes, Nox, MPUV, X1, might have forgotten one).
Lorewise, Jump Drives are literally attached to Q-drives, they use some sort of radiation or wave generation to open up the wormholes and then travel through em. So you can't have a Jump Drive without a Q-drive, and snubbies are too small to mount a Q-drive.