No his van I will be fine, I know because mine is towing more trailer.. You WILL need a weight distribution hitch, and 5th gear on the trans is unusable so your looking at around 10mpg, but it will do it and do it safely. I do want to add a good trans cooler to mine, but that's about it.
I have a simular unit, and my main issue was the 8,000 btu AC unit was way under powered to cool the unit. I ended up putting in a 12,000btu unit and it is much better but I had to "customize" my brand new unit which did not make me happy...at all.