I've been using a Powerwinch 912 for the last 15 yrs. It has a single
line pull of 3500 lbs. and a double line pull of 6000 lbs. The block &
tackle for the double line pull is included as are all the electrical
lines. There is enough cable to run to the car/truck battery. In my
case, I have a F150 pickup and I run the cable back and keep it in the
cap out of the weather. I have the Powerwinch attached with shoulder
bolts on top of the winch stand. I only use the Power winch for
retrieving the boat, after I have the boat firmly on the trailer, I
unhook the Powerwinch and snug the bow up with the hand winch, then
remove the Powerwinch and store it in the truck, out of sight. Its easy
to load a boat with the powerwinch because you can use a lanyard to
operate it while you stand on the dock aligning the boat. I have a
roller type trailer, so I don't have to back down as far as one would
with bunkers. This arrangement is good also, because in case the
Powerwinch fails, you always have the handwinch backing it up. If
anyone is interested in seeing a pic of how I have the winchstand set
up, I'd be glad to take a pic and post it.

Happy boating
====
Norm