There are currently two major mods. The NYGM and the Grey Wolves.
NYGM is aiming for pure realism only
GW is aiming also for realism, but it balances between gameplay and realism. Also, there´s alot of new graphics and sounds included.
I really cant point you the right mod, you have to test them both and decide which one to use.
PS. Welcome to SubSim! Enjoy your stay!