As stated by most of the above, with a GVW of 16,540, you're looking at a pin weight of possibly 3300# or so...My 5er has a GVW of 16,950# and loaded it's now at almost 16,000# with a pin weight of a little over 3300#....Forget "dry" or "empty" weights, nor realistic.
Forget 1/2 ton, forget 3/4 ton, even with their "new" and "higher" GVWR and GCWR ratings. At the very least your're looking at a 1 ton SRW truck.....Don't know where you tow, but I tow in the mountains on curvy, mountainous roads and I prefer the dually for it's stability when towing. Having towed the same 5er with both SRW and DRW trucks on the same roads, I can say from my experience that the dually offers a more stable towing experience.
You asked and a lot of us will tell you from experience...if you're going to buy a heavy 5er, make sure you have "enough truck" to tow with and one that you will end up being glad you got....if you don't want a 3500 SRW truck or a 3500 DRW, then you may want to consider a lighter 5er.
IF later on you decide to purchase an even heavier 5er later on and you purchase a 3500 SRW or 3500 Dually, you will at least, at that time, possibly already have the truck to do it with.
The 2013 Ram 3500 SRW trucks and 3500 Dually's have new frames, medium duty tranny option and much higher GVWR and GCWR ratings then they did in 12'..
"Am I being too conservative? My colleagues at work all tell me I am being WAY too conservative, that even the 1/2 ton RAM 1500 would pull this 5th wheeler but "for sure" the 3/4 ton RAM 2500 would. The only thing they say I would be gaining by buying the RAM 3500 is a lighter wallet and more trips to the diesel pumps."
Your colleagues don't sound very "rv savvy"..IF it were realistic, I'd like to see one of them hook that 5er up to a 2013 1/2 ton Ram truck, meet me at the bottom of I26, from TN into NC...I'll be waiting a the top, and they can tell me how that worked out for them...(didn't even put them on some secondary very mountainous curvy roads in WV:))
Hey, it's YOUR money, YOUR 5er, YOUR truck...YOUR call...most are just trying to tell you what kind of towing experience to expect with that amount of weight and what truck would probably make you the happiest when towing....
If one is going to purchase a 16,500# GVW 5er and knows they're going to have to pay for a truck to tow it...at some point, diesel fuel WILL figure in...it is what it is...IF YOU WANT to save money "at the pump", buy a 1/2 ton gasser and a pop-up...it is what it is...I need a 1 ton dually because the wife and I WANT our 5th wheel, so we know it's going to cost more to tow it...BUT that is what we WANT, we don't want to downsize and with that will come some sacrifice to have and enjoy the camping experience we want...
..........at the VERY least, I'd want a 1 ton 3500 SRW truck, if you opt for a "mega cab", I'd go dually...Mega eats up some of it's own GVWR as opposed to the crew cab...