You have a beautiful bus, I'm jealous of your engine driven AC units. My bus is very similar to yours, it is a long Thomas with 250HP.
I stored my bus at a covered parking RV storage lot in Lewisville. Then in the evenings after work (and on the weekends) I would drive the bus to the Dallas Makerspace on I-35 and Valwood. I could work on the bus late into the night there where they have all tools, AC, bathrooms, and electric power. The have a 240v plug right next to the truck receiving bay so I built a 240v splitter so I could run two 120v AC units in the bus and not die from the Texas heat. There are plenty of RV storage units south of the Makerspace that would work for you since you mentioned living Arlington.
My tiny home blog: TheBigBusTheory.wordpress.com