you can get a "proper" M4 configured rifle by purchasing a CT "pre-ban" lower.
namely, any lower that is
1) manufactured prior to September 1994
AND
2) is not a "Colt AR 15" or a "Colt Sporter."
There are a few stores in CT that have pre-ban lowers in stock, such as Newington Gun Exchange (ask for Lars) and JoJo's.
But they're pricey.