Best advice on Jag... Don't buy one.
Waste of time, it ain't that good to start with due to lack of game base, yet another great Atari , Release, and then destroy it project...
The ONLY Game worth playing is Jeff Minter's TEMPEST 2000, which in all fairness is on PS1 as Tempest X3
One of my old mates owns quite a lot of Jag stuff, it sits in a box...
Emulation wise, not a lot really, I seen a rough as hell emulator a couple of years ago that tried to play Tempest and failed miserably... Never bothered since