I've read many of the geothermal posts, and there's a ton of good experience being shared. I need some very specific answers before I drill deeper, however:

I've got 4 heat-pump/air circulator systems,serving 4000 sf. Two of them are over 20 years old and need replacement. That, plus the 30% tax credit, plus my green conscience, has me considering geothermal. I'm on the Delmarva peninsula (east coast), so have equal heating and AC needs. But not too many (none?)contractors advertising around here.. So, two questions, really.

(1) I'm interested in hearing of other geothermal experiences in my geographic area, including reputable designers/installers. And

(2) what are my options in terms of tying into existing duct work (and air handlers?). 3 of my systems distribute air from the attic, one from a crawl space. Do I need 4 geothermal units? or only 2 (attic + basement). Can they tie into one closed loop system, or does each need its own closed loops? btw, I do have a small, full basement - ie - not limited to crawl space and attic.

Thanks