Mine isn't a SRW, but I'm going through a similar dilemma. Like you I have E rated 16" BFG Commercial TA Traction tires. They've been good tires though a little soft for my current camper - a 2014 Lance 1191. The tire tread is fine, but they are 6 years old and have dry/cracks so I'm going to purchase new tires. This morning I finally made the decision and purchased the 6 Vision Heavy Hauler 19.5" Wheels and G Rated tires from Mario at http://duallywheels4u.com/. I've read good things about Mario in several different forums. I spoke with him at length and was very comfortable with him. The price is $3,688 shipped to my mechanics store for 6 Vision wheels 2 x Sumitomo ST718 Drive on the front and 4 x Sumitomo ST918 Drive on the back, 32 Lug / Washer Set, Force Match Balanced. I went with a 2.5" taller tire because I'm geared too low and my motor is spinning more than I'd like at my preferred driving speed.
In the end, there didn't seem to be a right answer. Some people like 19.5's, some hate them due to the harsh ride, etc. My truck is dedicated to the camper and I don't use it as a daily driver, so this may not be an issue for me. I finally decided that since I had to make an investment, I might as well spend the extra and get the load/safety headroom. In addition, it may help with future resale should I ever be crazy enough to sell the truck (Love the truck).
It will be 10 days to receive them. I'm doing a front BigWig Swaybar (1.5"), front Sumosprings, and Rear Roadmaster swaybar (1.5") at the same time. I already have Supersprings and Timbrens on the back plus Monroe RV HD GasMagnum shocks all round. I'm having my mechanic do all the work. Since I'm making several changes at the same time, I won't be a good reference point, but I will try to post a review anyway. I understand the first 500-1000 miles on the 19.5" H rated tires are very squirmy, but they settle down past that.