You already got something in mind or just looking for an ak? Whats your budget like? I'd be happy to give you the lay of the land in the ak world if you're unfamiliar.
AJC Sports in Katy used to have a few on the wall, but they closed up shop from what I hear. I haven't been by there to verify, but heard this from a guy at the range, might be worth a call if you're traveling I-10. There's also tactical firearms in Katy, but sheesh...prices were always sky high. They're under new management and I think some on the board stated their prices are somewhat better. Think selection may be limited currently from what I've heard.
I'm sure some of the bigger shops in town will have some, just might end up paying a bit more depending on where you go.
On Houston's east side, Trinity Bay Tactical is heavily into AK's and AR's. They are nice people and I've known some of them for over 15 years. They cater to Hog shooters and specialize in Hog buster rifles. Check my signature line. There's a link to their site.