Mile marker makes the kit that works for these pumps- same one used for hmmwvs/ hummers.
18,000 lbs is flippin huge. Run that to a snatch block and back to your truck- you ar now trying to hold 36,000 lbs with your 8,000 truck. Dont pull crooked or you will ruin your frame.
Yes a dedicated pump is best, no there isn’t going to be a ready made kit. You might need to relocate battery or other stuff to make it fit. But what you are taking about doing is major modifications anyways.
Forget a pto.