Chris I've found many shops selling these items near military areas. For example if your go to Sattahip, this is a large Thai Navy area 30K south of Pattaya, and there are at least half a dozen such shops in the main streets of the small town making and selling patches and military uniforms. So thats my tip wherever there are large military bases there are these shops.

__________________
The Truly Wise Man Never Plays Leapfrog With A Unicorn