I'm not sure if you can buy one being a non-resident (doesn't specify), but many of the counties you listed have public hunting units. Some get a little crowded on holidays and the campsites are bare-bones, but I always manage to have a blast. I'm all the way out in Lubbock, and I try to make a trip (9-10 hrs) to one of the WMA's in and around the national forests in that area as often as I can. A non-resident license is $315 and the APH permit is another $48 (leases are in the thousands per gun, and you still have to buy the license). Not alot of trophy bucks, but if you're in it for the meat there is no better deal. Plus, they are CRAWLING with hogs and it's open season year round on those fat delicious bastards. A few even let you predator hunt at night. I've never paid more than $6 a night for a campsite (alot are free), and most are within 20 mins to some sort of hotel/inn if that's more your speed. Here's a link to the official info, and if you're interested I can steer you to some of my favorites.
TPWD: Walk-in Hunts: Annual Public Hunting Permit