Depends on whatcha want. Just about any place can help you with sights. They all have those and usually several to pick from. A couple of places I can think of - GT Distributors in Dallas has Vickers Tactical stuff for Glocks as well as the usual Glock accessories. Whitewing Weaponry in Plano and Denton carries Zev Technologies. Any D/FW gun show there are one or two Glock armorers with all sorts of Glock stuff.