Escapees RV Club has a mail forwarding service based in Livingston, Texas, which gives you a Texas address.
No state income tax, and RVs are not liable for personal property tax. The state sales tax is 6.25%, which is pretty brutal on a motor home purchase, but annual licensing on a motor home is in the $300 range (unless you have a Purple Heart, Medal of Honor, or are a Pearl Harbor Survivor or former POW, in which case it is $3/year). (They make up for it by taxing land and buildings at a usurious rate, but that's not a problem if you don't own any.)
Livingston is also a cheap county for car insurance (the fulltiming surcharge negates that for a MH, but not your toad.)
Driver's licenses aren't hard to get, and Texas Concealed Handgun Licenses are recognized in a bunch of states (considerable training is required to get one, but it can be done in a weekend. Qualification at a range is part of it.)
We haven't signed up with Escapees yet because we haven't sold our house, but we will.