If the panel/autopilot setup is what you're looking for, you can always do an engine swap if the compressions keep dropping significantly from annual to annual. 60/80 is too low to fly. That being said, i'd rather have a fresh (new360) engine, and a whatever panel, than an old just about used up engine and my 'dream panel' . . I don't know the size investment you're looking to make, but a new(or OHd) engine may just land in the same price bracket as a major avionics upgrade with a different, lower timed J model. depends on what you need the plane to do for you, and how much of a retrofit you'll want in the long term. But a good pre-buy inspection is a MUST in older Mooney's. Keep lookin around too, I'm sure your right match will show itself before too long.
go safe,