We use one of the inexpensive free standing spring frame types you can get a Cabelas, Bass Pro, or just about anywhere. They are light, store small, go up fast and you can set it up anywhere. Our trailer has the tent on top, cooking on one side and storage in the back. Last thing I would want is a shower with the associated puddle next to the trailer. If you don't "live" around the trailer like a trip to the beach, etc. or a ground tent off to the side I could see it might be nice option. Some of the compact truck campers have fold down shower frames with curtains similar to what is shown on the trailer above that might be a source.