If you haven't seen them already, there's a company here in the States called Vernalem. They sell 50 and 60mhz 68060 processors, and also have a big Amiga logo on their site. They may also upgrade or repair CPU cards, but I have no personal experience with them.
In my experience, the standards in the computer repair industry over here suck. Most people don't know what they're doing, and getting a good tech is difficult at times. Usually you're best off doing it yourself!