You're going to need something sturdy enough to support the holstered gun. I can't think of too many other materials that will lend this kind of support. You don't want to draw the holster right out of your pants along with the holstered weapon.
What's wrong with a leather casual belt?. I think a military style uniform web belt is out of the question. I've tried my old AF belts and they did not provide the proper support or security.
You might try a different holster such as an IWB.