I used Carolina Carports for my Camper Cave...
No problems with the install and it still looks great.
Looks like they deliver/free install in your area.
http://www.carolinametalcarports.com/north-west-rv-cover-packages.htmlIf you are really serious then I would recommend the following.
13 ft legs minimum ... Easy to work on the top of the camper when off the truck... And the camper/truck on 4wd should fit with the closed gable ends.
14 wide minimum
25 ft long minimum... My camper and truck is 20 ft... I wish I would have gone with 30 ft.
Get vertical siding and vertical roof..
Water runs off easily on the vertical roofs along with snow. Vertical sides do not collect dirt and moss etc with vertical sides. Easier to clean too.
Here's mine.. Wish I would have got the vertical roof and sides. Did not know about that option.

I just finished a new Metal workshop 25x30... Insulated, 13 ft walls 2 roll up doors... 16x12 and a 8x7... I ordered it from United Carports. I notice that they are in Oregon too...
3 day installation.... The install team was outstanding! Not saying that in other states the service will be as great..
If ordering you need to understand all the segments of the configuration/build. I added full certification, thus the plans were included for permits if needed or wanted. Heavier steel wind/snow ability. Would be glad to help... PM me if you need pointers.
http://unitedcarports.com/nwJim