I tow a 30wrs with a 2005 ram 2500. Tongue weight is 1450-1600 with no cargo, (I only hall kayaks in the back) measured by my sherline scale. I don't have a generator in the front so add some weight for that, if you option for one, since it is mounted in the front. I had to add a class 5 hitch as well as upgrade the shank and trunnion bars. When I bought my trailer the dealer had a 34wrs on the lot. They have been available for a few years as a custom order even though they just recently showed up on the website. It was the same exact configuration as a 30wrs with 4 feet added to the back. This put more weight behind the rear axle so the tongue weight was actually less. I don't have specific numbers since a 40 foot trailer wasn't something I was considering.
Also, for those that are curious, I checked my tongue weight as I filled the fresh water tank. As you start filling tongue weight decreases 25-50lbs, then evens out, then increases by 25-50lbs with a full tank (110 gallons). It is not affected very much since it is positioned between the rear axles.
2015 Work and Play 30WRS
2005 Dodge Ram 2500 4x4 diesel