24ft.... easy to find used, much easier to resell than just about anything shorter. You'll soon find the extra space up front can come in oh so handy, whether it's to carry more stuff, or room to lounge in front of the car in the case of rain.
Perhaps easy to find used in your area...not so much here in Eastern Washington. Haven't been to serious in hunting yet but the only one I have found local was 10 years old with several mods that I don't need...and he was asking 10k for it..
Just out of curiosity I searched around the Phoenix area. Found a few that are more like what I am looking for...normally I would ask my buddy to go look at it for me and if worth it pick it up for me but he is at his place up north...