The add I saw is
Specialized ECU Repair - Porsche DME Repair, Bosch and Motronic Control Units. I don't know anything about them. Your on your own.
I used a standard universal coil in my test fixture for years and tested hundreds of CDI's. The old Porsche CDI could handle 25AMPs @ 600 V. There shouldn't be a problem but it would probably be best if you use the coil it was designed for. I would test the CDI's for 24 hours at 10K RPM.