One thing that Thai cities are certainly not sort of are picture framing shops, they are everywhere, it won't be a problem, go down a street for far enough and one will inevitably turn up. Some of the local resident expats might be able to help you with the "best" title, but that would depend on whether you are talking about the cheapest or highest quality service. Most should be OK as they are forever framing pictures of the royal family so tend to do a reasonable job most of the time.
from the palace end of town, travel into hua hin, at the first set of traffic lights turn left, 20 yards down on the right hand side is a framers.
Yes, we've tried several and that one is definitely the best in town imo. It is called "All Frames".
My brain is like an Internet browser; 12 tabs are open and 5 of them are not responding, there's a GIF playing in an endless loop,... and where is that annoying music coming from?