Isn't the diff. between the PaveLow and the other xH-53xs just the electronics loadout? Perhaps you could simulate the PaveLow by using the MH-53E Sea Dragons from the USMC OOB, and then manually editing the EW rating for the particular unit, and then renaming it.
You may also want to bump up the experience/morale to better model the Night Stalker pilot you assuredly will want flying that thing ...
Here's the standard MH/CH-53x:
http://www.globalsecurity.org/milita...h-53-specs.htm
Also, it looks like they're up to a PaveLow IV -- MH-53M. The main difference seems to be the electronics loadout.
http://www.globalsecurity.org/milita...aft/mh-53m.htm