I have a similar truck to yours and I would definitely not want to go back to a gasser, even with a trailer your size/weight. My wife's uncle, who is an excellent fabricator, made us a custom very heavy duty frame mounted receiver for our fifth wheel and we purchased the Swagman Model 64940 4 bike rack for a 2" receiver. This rack is rated for use on RV's including fifth wheels. As much as our bikes are not super expensive, this system is very stable and works well.
We are also thinking of going the kayak route and I'm seriously thinking about purchasing a good quality inflatable kayak, like an Aquaglide. Their products are beautiful, very stable, and easy to set up. The reason for this is because I personally don't care to put a less than attractive rack on my truck and worry about the kayaks possibly hitting the trailer (my truck is also a shortbox) and risk damaging the truck loading and unloading them.
Just a couple of things for you to think about.