sf_plane_nut
I don't know about specific clubs in Rhode Island. I also live in Eastern CT (about an hour from Providence). There is a club that meets in the Hartford area, but that would probably be too far of a drive for you. However, I know a couple armor guys who also live in RI, so my gut instincts tell me there is a club there, though I don't know if it is armor specific or more general. I can e-mail them and see what I can find out for you.
As for shows, there are two 'big ones' that I go to. In March there is ValleyCon, which is in Chicopee, MA. It is an IPMS style show, so the builds run the gamut. It is a really well done show that is put on by the Wings and Wheels club.
Then in the fall, at the end of September, is AMPSEast. This is in Danbury, CT and is an armor only show. Again, a really nice show. Lots of good builds, lots of good vendors, and a ton of fun.
I am pretty sure there are also a couple of shows in the Boston area, or out on the Cape. In addition, there is DownEastCon, which is up in Maine a week or two before ValleyCon.
Believe it or not, you are in a good spot. There is a lot of modeling going on around you. You just might have to explore a little to make contacts (this thread is a good start).
I'll contact a few guys I know and see what additional info I can get you.