newp, at least not by conventional methods. all rompler keyboards are just that - read-only. you'll have to record the samples yourself - and possibly loop them where required. it's easy enough if you're only doing it for a few sounds though, and tends to be dead simple for drum sounds.
line-in isn't necessarily crappy though. a good quality cable+soundcard and it should be fine.
Or you might wait a few years for the MAME/MESS guys to get around to emulating them, since they're doing pretty much everything with a CPU these days.