I was sort of in your position 8 years ago when we purchased our first TT. I poured through all of the stats and floor plans to find the best trailer for me. I also checked them out in person. Major differences are that we were weekend warriors and a long trip for us would be 1 week. Build quality was paramount to me and since I always buy used the dealer was not an issue. There are a few brands that take build quality to a different level and eliminate the persistent problems the others have. These brands would be BigFoot, Airstream, Oliver and Escape. That being said, the compromises they pose in terms of lack of slides and relatively small size would most likely be deal killers for 8 week excursions. Let alone the cost.
The trailer we chose was a used Bigfoot 25 ft. rear queen. The trailer was a superb platform and eliminated most of the usual problem areas. 5 year depreciation while we owned it was zero.
Look at my signature and you will see that floor plan and size became more important than build quality. The current trailer is good but nowhere near the Bigfoot. Prioritizing your needs is difficult especially the first time. Good luck with your search.