Talk to whoever is going to do the milling and use the library they suggest. The other option would be to use the Dess library for their multi unit abutments and then have any competent milling center do it.
If you have the wright scanner ,library and knowledge how to use (torque, matching and a few other things) you can send out the files only, if not i would additionally send out the models to be on the save side especially at the first cases . a good mill center is able to compare your scans and their own , scanning is the cheapest part .