All the parks you mentioned have good size lots with room for your 5er and truck. The Palms is closer to the majority of Marine air traffic. Las Quintas is the best of the three dollar for dollar. You might want to have a look at Sunridge RV Park. Huge spots and lots going on. A few years ago they had management problems but not any more. The current management have the residents best interests at heart and work really hard to make your stay enjoyable.I think sites are $340.00 per month. The park mentioned in Welton is owned by the same people as Sunridge.
Just my 2 cents worth