Can't comment too much on trucks as I started out with what I thought would be big enough ( GMC 2500). It was great for the trailer but I bought the truck camper and all of a sudden the too big truck wasn't big enough.:S
As far as trailer, for us it was the floor plan. I started out, no rear slide and no bunk house; guess what the Jayco has. Rear slide and front bunks> BUT the way it is laid out is great for two of us. The bicycles go in the front and the slide gives us a lot more room. Go to some shows and look and sit. The floorplan will "talk" to you, then sit and ponder in the chosen unit before going to look at more.
Good luck with both of your choices/ decisions.
Brian