Nobody...if your Marquis dealer is telling you that you are out of his service area then you'll have nobody to source/install warranty replacement parts if needed unless you are comfortable having them shipped to you through the dealer and either installing them yourself or paying a local spa tech to install them (something I would never recommend but I have seen it done for those who consider themselves handy and are comfortable working on their own hot tub) you'll need to know how to diagnose, use an electrical meter, etc. so again it's not an ideal situation.
Good Luck!