The hitch is the exact same one you would have gotten if you ordered an OEM one from new. The little letter/sticker is a CYA, yes.
The Gasser Liberty I believe is 5000 lbs. The biggest issue is keeping the transmission cool.
As for the wiring, it depends on what you want to do. If all you needs is a flat 4 wire, they're about $30 in the aftermarket and take about 20 mins to install inline with the tail-light harness. If you need a 7 way (trailer brake), you're looking at a whole 'nother ball of wax.
