I find Cabelas has high quality equipment that will last a long time however it is usually expensive and heavily constructed. They have this model in the store I recently visited. It has quite a few good reviews on the site.
We originally purchased a similar "first generation" model from a different manufacturer which worked fine but this Outback one has some nicer features, especially the removable floor...that makes it much easier to dry it after using it as a shower. It also has exterior towel hangers, etc. The support "poles" system looks similar to the one you mention...
'01 Ford EB50p Quigley 4WD