Clubman roof rail install?
 

I picked up my slightly used Mini Cooper S Clubman with 10,000 miles and LOADED in February. I'd been delaying my plan for a Florida trip and then I got the car.....roadtrip!!! It was great and I learned a lot about what to bring.
Now I want to travel farther and cheaper and would like a roof rack (or roof mounted tent) and need some help with basics. The loaded vehicle doesn't have roof rails, but it looks like they can be installed by someone reputable. Any suggestions about that? Dealer, OEM parts at a shop?
Any other suggestions are good too, like where to stay on the Maine coast in August.
Thanks!