Don't know if you've gotten this taken care of already or not, but I just thought I would offer my $.02...
Another acceptable way to tackle it is to cut off the outer skin leaving a lip of 3" or 4" around the permiter, replace the core, bond the skin back on and then grind/glass/fair/finish the cut. This doesn't give you the opportunity to check the condition of the stringers and other structural components like Gilligan's method does, but it is generally less intrusive/expensive.
If you think you might like to try and tackle this yourself, I would be happy to discuss things I have learned over the course of my first transom job on a Mako 17.
As far as local shops that can do the work, I've only seen the results of one place, and based on that I couldn't in good conscience recommend them. PM me if you would like to know what shop it was.
Good luck.
Brian
P.S. - If your boat happens to be a V20, check out
Wellcraft V20.