If the Libby you're looking at has the factory tow package you're in great shape. It will tow your boat with ease.
If there is not a tow package on the Jeep (the Class III hitch, wire harness and the mechanical fan) then it may be worth looking for a Liberty that has it, or if you're mechanically inclined add the components yourself.
The hitch is easy - many places sell the hitch. The harness can be purchased from aftermarket places but the factory harness is plug-n-play - if you can find one. Several online places have them but depending on whether the Jeep you buy has an EVIC overhead console you may need to buy what's called a supplemental harness.
The mechanical fan can be purchased from Mopar, the fan clutch from places like Summit Racing - but the fan shroud and electric fan are difficult to find. I bought mine from the place on eBay:
HD Shroud & Electric FanHope this helps!
Bob