This heater will warm 10 liters (2.5 gallons per minute) by 90F, or 55F to 145F (much more than you need)g so it can quickly fill your Jacuzzi with 100 gallons of 105F water - just need to set it for about 4 GPM so you get 105F water, not 145F.
Amazon.comIf you are in a campground, no problem, you can fill from your shore water supply, and drain into the septic system at the park! If dry camping, then hopefully you will have at least 100 gallons of water, perhaps dual 100 gallon tanks?
Truck to tow it with, that will be a problem. Dually truck for sure. The Freightliner has a tighter wheel "Cut" or it can turn close to 45 degrees when going slowly into the campsite.
The F-350 dually truck is also nice, and probably what I would pick myself. It has a 5,500+ pound cargo rating, so will handles the hitch weight, anything I decide to carry, and much more in the pickup bed.
Fred.