Well, if you haven’t tried GWX yet(Mega Mod), you must definitely try it once to see if it fits your taste. It add much better graphics and environment with realistic damage models, ship sinking times etc...
http://www.thegreywolves.com/gwx3/
If you are into Realism, I can recommend you H.sie Hardcoded Fixes as well.
http://www.subsim.com/radioroom/showthread.php?t=174225