Also watch your tongue weight and GVWR. I don't know what your definition of tool box is-- but the one I carry weighs about 100 lbs. and if I had a bigger box (like the one I'm thinking your looking at) I'd sure as heck fill it (wouldn't be able to control myself).
Anyways here's what I'm thinking.
Your trailer's hitch weight dry is 500lbs.
2 Propane tanks= 65lbs
2 batteries-= 130lbs
and now a tool box= 100lbs
Your at 295lbs + 500 hitch= 795lbs tongue weight. That 800lbs weight needs to be figured into your weight planning. Everything you put into your truck (including the trailer's tongue weight) goes towards (or deducts from) your GVWR which is 7700 (looking at the owners manual). Check out your door sticker to see if you are getting close to that figure. If you want... but here is the kicker:
****A class III with a WD system on your truck can carry 740lbs...
(right out the 2006 owners manual)
I don't know that 100lbs is a big deal on your TV, but I was bored so I looked it up. Your probably GTG. I mainly wrote this up for ppl that have smaller SUV's that might have issues.
These weights add up fast!
Good Luck my fellow Jayco floor plan partner.