Farmkey did mine. I would be happy to use them again. It was all very efficient and the technician was very good. a lot depends on the technician covering your area. I have heard of a few dodgy experiences in different areas with Freezemark.com!
My very first one was done by Farmkey, and then when there was a change of management and Mary started Freezemark I went to them, and have used them ever since.
I used Farmkey and they were very good as was the lady who did the actual Freezemarking taking time to explain it all to me before she did anything as i was a little worried about it.