This is the only Map-pack out for FH2 right now (that I know of):
http://www.bfewaw.com/map/Unfortunately, no servers (that I know of) are currently playing those maps and I'm not sure if they have Single-Player (SP) support.
There was a project on the old forums of someone trying to put SP into the 2.15 maps that didn't have them yet, but I'm not sure what became of it. I'll try to do some digging and find out. I'll get back to you.
EDIT: Here ya go:
http://battlefieldsingleplayer.planetbattlefield.gamespy.com/forums/index.php?showtopic=13215 That's the FHSP MiniMod, adds Single Player to the maps that don't have them, and I think it adds a few more Single Player maps as well. It's currently only in Beta, so read through the thread if you are having issues.