I guess the question was as much about hitch weight as capacity (since I would be new to 5ver).
Math follows:
If I assume 10-15% tongue weight of 16K = 1600-2400 lbs. With fuel (1000 lb), plus hitch and DW (500 lb), that would put me just under 4000 lbs (payload of a SRW - 4078 lbs).
But I have seen people indicate 20-25% tongue weight (3200-4000). That again puts me at 4000+1000+500 = 5500. About the payload of a DRW (5607 lbs).
So depending on what the actual hitch weight is, I could be up against the weight limit for either SRW or DRW.
Bigger is "always" better. I just was wondering if anyone made a SRW work.