Cdaddy,
Welcome!!!!
Check this thread out that a fellow member just recently posted about his truck (a v6 at the time, with the trailers he was looking at and the possible truck upgrade...
Like it has already been posted, your limiting factor is the trucks payload. The next limit is usually the RAR, then possibly the trucks receiver hitch rating.
He is in a similar situation as you, and is picking up a Ram 2500 today vs a new 1500 Hemi due to the payload. Yes, his current truck has/had a v6, but a new Hemi would not have gained any major payload to justify the cost as he would probably still be over the trucks rating. Understand the that "brochure" dry tongue/hitch weight of a trailer does not include the weight of the propane tanks or a battery on the tongue!!! Those alone add ~120lbs for 2-20lb tanks and a battery, or ~160lbs for 2-30lb tanks and a battery.... If the "dry tw" is about 775lbs you are already at ~900lbs tw or ~940lbs tw, before even loading anything else in the trailer. And if that model has a front pass through storage, that weight is on the tongue, plus if you haul fresh water depending on the tank location, etc....
The weight adds up very quickly. And it seems it grows as we own our rigs, but seldom goes down. I read a great suggestion (on here I believe it was) that was to go through the trailer (rv) at the end of each season and remove anything that wasn't used at all, and possibly those items that were only used once or twice during the entire season. It helps keep the trailer weight in check.
Good luck!!!