Looking to buy a used ski and/or jet boat. Traveling to the USA on the 10th of July and was wondering where in California (OC, LA County, Ventura County) can i go to look for used skis, jet boats and parts?

Also, considering a budget of 4000-5000 tops for a ski, 4-stroke 3-seater and relatively ok, what Yamaha ski would be the best? Looking to use on fresh water and for family recreation.