Hey Jon,
Are you looking at the metallic green 914 in CT? That was for sale a while ago in NY (Albany area) for quite a bit less $$.
As to your question: your mechanic will need be more knowledgeable about Subarus than Porsches in my opinion. The 914 is a very uncomplicated car so that part of it should be easy, or at least easier.
The difficulty in getting a non-running project going will be trying to figure out has and has not been done. In this case, it will be the electronics around the WRX motor, controller, etc.
I'm sure you can get a new harness - plenty of these conversions have been done - and maybe hooking it all up will be all that's necessary... but maybe not.
Also, lot's of help here at 914 World if you decide to take the plunge.
Good luck!
Tom
(also in the Northeast)