towing length - Nissan Frontier

OK, guys and gals,

Iv'e viewed this forum for awhile and am getting close to buying a TM. Been saving my milk money........ Anyway, my TV is a 06" nissan frontier crewcab pickup 4X4 with tow package. Now I know I can pull 6100 , (lets round down) 6000 lbs. I have a tongue weigh limit of 600 lbs. Furthermore my truck's length is 17ft with a weight of around 4500 lbs. My eye has been on the 2720sd. But recently I have been thinking about the 3124 ks . I don't need a second perm. bed so the 30something model is not what we want. So, even if I maxed out the 3124ks with 1000 lbs of water , propane, stuff etc....I will still be under the 80% load figure. Now then, my question, would that 24ft be too much length to handle safety?