There is this Pond in Halifax. It has a boat ramp for the big boats and you can use a kayak. Its not totally great for off shore fishing. But it can be done. http://www.mass.gov/dfwele/dfw/habitat/maps/ponds/pdf/dfwmonpo.pdf
Are you talking about Monponsett Pond? You can go small and probably a "Bass Tracker" type boat there.
The "Nip" is just off route 24 at exit 15. Has a launch, but it can get shallow, gotta watch the depth.
For the Cape, ( large and small boats) I would recommend Peter's Pond in Sandwich, MA. For the Cape, large boats, I would recommend Mashpee-Wakeby, in Mashpee, MA.
I never fished Long Pond in Lakeville, although it's only 10 minutes from my house. I wouldn't mind giving it a try. I have a small John boat with an electric 40 lb thrust motor.
The place down in Wareham that MikeC tried to get a gig at last year is another consideration, Glen Charlie Pond.
The thing is, some places are better suited for differing type boats and we may have some anglers with no boats at all. That's why the Quabbin Resevoir, where everyone doubles up and rents a boat and perhaps a multiple bed bunkhouse might be the way to go. That puts everyone on an equal footing, as far as a boat is concerned. Of, course that's an over-nighter and it is gonna' run into some money and scheduling problems. ( Could be a good drunk though )