With a travel trailer, your hitch equipment (weight distributing hitch and possibly sway bars) would weigh 150 lbs less than a fifth wheel hitch. Also, the average tongue weight on a travel trailer is 12 - 13 percent of the loaded trailer weight, where pin weight on many fifth wheels is closer to 22 percent.
With those percentages, comparing a 7000 lb TT with a 7000 lb FW, your truck would need about 1000 lbs of available payload for the TT and 1790 lbs for the FW.