Do the conversion, disconnect the gas though, just turn it off from the back and plug the pipe. Get all your MPFI parts off an EA with gas (modified TB, gas computer, converter). Use an unmodified loom though. When you're done with installing the manifold and related stuff, take it down to the gas mechanic with the all the plumbing and stuff that came off the gas manifold and he'll put it all on and wire it up for about $200.
That should work I guess.