Drake, I don't know of a source who sells the stamps in the DR.
However, I looked into it in Spain years ago. It is an item which is mostly made by or for companies which franchise the business idea.
Have you ever done it?
When we looked into it (we had to find a "paving" solution for 8000sf.), we learned that for each pattern you need not just one interlocking hard rubber stamping mat, but
several, so to be able to stamp 10x10ft to 12x12ft segments at once to get an
even pattern. It takes quite some experience to catch the right window of opportunity in the concrete curing progress not to sink in the "mud" and to still create a good pattern. Contrary to what is seen around here, the correct staining technique is not to paint the finished hard product, but to stain the top layer of the still wet concrete before applying the molds. That too, is a technique which needs some testing to get a good, not grayish nor over colored result which goes deep enough into the concrete so that wear will not show in the first two months.
Yet it was the cost which finally turned us away, paired with the risk of poor and difficult to repair aging. Concrete slabs to tend to eventually crack here and there... especially in regions with earth movement. Given the size of our project at that time the acquisition of the stamping mats was not really a big item in the equation.
I don't know what project you have in mind or if you plan to go into business, in which later case I'd suggest you look for a quality provider in the US.
Our project included a large parking lot, leading into a drive-thru 3-car garage and paths and ways throughout the property. We finally settled for colored city traffic graded concrete pavers... the look we tried to imitate. Actually, we wound up with the "real" stuff for about the same price in materials and similar but fool proof (re-doable) installation effort, a more service-maintenance and repair friendly finish and a durability which by far surpasses stamped concrete. The result was stunning and people visiting that property rave about the looks.
There are companies in the DR which make decent quality pavers. But I don't know their pricing.
Just some thoughts I thought I'd share with you...
And some pictures of the finished result using pavers too:
Parking lot:
Paths and ways around the home:
Round shaped layout of small pavers (the same was done around some large palm trees):
... J-D.