Pet City has nice feeders! I've used them before when I had stubborn corn snakes who needed a live meal or two. Currently, I'm buying rats from Reptile Select. They have feeders (assuming you don't order a boatload at once) and they can pre-kill and freeze for you as well! I recently ordered about 10 frozen pinks for my baby ball. The rats are in good health!
Edit: Reptile Select is off of 290 and Jones. Not sure what part of Houston you're from.