Here are the 3 best local options - IMHO.
1) Buy the RB templates from Mazdatrix and do it yourself. It's not too hard, and you know exactly how it was done.
2) A little more expensive. Get David Girod to do it. He is pretty busy right now, but he knows porting 12a motors.
3) Most expensive. Get Juan Delgado to do it. He is very good. All you will need to do is drop it off and have some money ready.

Personally, I have no time to work on my own car right now, so I am going to have it done for me. Normally, I would have David Girod do it, as he is a friend of mine and is completely capable of doing it. Since he is really busy, I will probably have either Juan or Sammy do it. Charlie at Mazcare is good also, but they don't do a lot of 12a motors. Mainly 13B-REWs.