Even the exercise of thinking out a kit bash is entertaining.
Say I wanted female Panzer Lehr.
These legs:

(Remove the center strap on the gators.)
Maybe these torsos:

(Anybody have a better solution? Green stuff WGA Panzer Lehr torsos?)
Helmets from the Perry DAK or 1/48th Tamiya infantry, which ever looks better. EDIT: Those helmets don't have covers which is a pretty distinct Panzer Lehr thing..... hmmmmh).
Heads... lots of choices. I love the Statuesque Minis ones. Maybe the WGA Female Cannon Fodder ones as if I'm sawing/cutting off the tops of their heads to fit helmets, plastic would be nice.
Arms, weapons, breadbags, canteens, etc., from the WGA Panzer Lehr kit. The same weapons and arms will help tie them in with male Panzer Lehr.
This is largely a thought exercise. I may make a few for sh*ts and giggles later. I won't lie, I would DEFINITELY buy a WGA female Panzer Lehr kit though.