Best supplement for arthritic cat?

My cat Tigger has had pretty bad arthritis for years, but I was hesitant about trying anything for fear of side effects. However it's now getting to the point where she really has to have something. I refuse to use drugs or NSAIDS, but have heard great hings about supplements like Cosequin and Synflex. Has anyone used one of the natural remedies? I'm leaning towards trying Synflex and adding MSM. I'm also starting hydrotherapy with her as well as therapeutic massage and possibly acupuncture. ANy othger suggestions would be helpful too. She already has a nice super thick high density orthopedic bed and gets a great diet with Wysong Uretic kibble (every time I've tried to discontinue it she gets UTIs), By Nature Organics canned food, as well as Paw Naturaw raw diets and homecooked organic meats and wild caught fish. She also gets wild salmon oil, CoQ10, Taurine, LCarnitine, B-complex, and digestive enzymes to help her touchy tummy. She'll be getting Resveratrol, RNA, and red clay shortly as well