I've bought firewood from the Live Bait Outlet in Lewisville, off of Mill Street and Valley Ridge Pkwy. I typically buy Pecan from him, but he sells other wood as well. I use it in my firepit and in my smoker. You can also try this place:
https://mitchgtm.wixsite.com/gtmaterials . I have never been there, but I've driven by it often. It seems like they have a good selection of firewood.