You will enjoy the new truck. The ride is quieter than any vehicle, truck or car, that I have ever owned. You will have plenty of power and capacity for the fifth wheels you are considering. I am not a buy something because I did type but we have really enjoyed our Excel and the only thing we have needed done was a slide adjustment.
I would second the Trailer Saver BD3. We had a B&W Companion in the last truck and they are excellent but the air bag ride of the BD3 is very nice and well worth the extra bucks, in my opinion. I installed a standard rail system from Curt in the new truck. It is a custom fit and was a bit a pain to install but it is very robust. We are making our first long trip with the new truck in a few weeks and I am really looking forward to it.