0.1mm tolerance is quite easily achieved, even on conventional (non-CNC) machinery, so that should be no problem.

As for set size dimension (bearing recess etc, where you can't really deviate from the size), these would normally be reamed out anyway.

"Engineering Machine Shops" or "Precision Engineers" in a phone directory will give a list of machine shops in your area - its how I go about finding workshops if I'm ever looking for a job.

Hope that helps.