Welcome to the FSM Asykr.
I assume you're referring to the Italeri M4 that they list as an M4A2 / A3 and so on.
You're best bet is to build the M4A3 version of the kit. Forget the M4A2 parts they include and commit them to the parts box, they don't include enough parts to do it right.
Finding references for the Marine Shermans on the net isn't an easy task, I'll look through some of the stuff I have here and see what I can find.
Here's a link to some completed models of the Marine Sherman at Tracklink.
http://www.track-link.net/gallery/USA_WW_2/subject/3
Hope this helps a bit.
Happy Modelling and God Bless
Robert