Imhoff Park in Kommetjie, Cape Town does do such a thing. Speak to Anne Anderson.
Ask her to be very honest about the quality of the vans she’s got available, because they might not be ‘pristine and palatial.’
Other than that all the parks on the Peninsula are municipal owned and run, and won’t have what you’re lookin for, I’m afraid.
If you speak to Eden Woonwaens in George they may be able to advise you because they’re pretty knowledgeable about the Southern Cape area.