The stock antenna should be fine for you if its in a good location in your house and want to listen locally. The closest simulcast towers for you would be the Troop E and Old Lyme sites. Also, program in the talk groups for your area and also any of the state wide talk groups. one thing I do on my SDS100 and 996P2 is I leave the ID search feature on just in case I get a dynamic talk group (65xxx series numbers that pop up and are not "permanent" groups) or an unexpected town / service from out of area ends up coming over the simulcast site.
I'm usually mobile through NL County since I work in the area. There are several other members here on the board that will expand further on things I haven't put up.