You could always spend about $34 to buy a regular trailer boat winch with a 20' nylon strap and hook and mount it on to your truck (
http://www.walmart.com/ip/Shoreline-Mar ... p/16606510).....a cross bar or 2x4 plugged into the front "post plugs" of the bed will work or a simple 3 or 4 to 1 block and tackle will easily pull your PA into the truck bed.
I have a boat trailer winch (1000 pound capacity) mounted on my Trailex trailer to winch my PA-14 on for just that reason.....a small 600 pound rated PWC trailer winch works too.
IMHO,you really do not need an electric winch....it only adds complexity....I tend to practice the "kiss principle"....or ..."keep it simple stupid"