as I stated a 1 page CV that I renamed "freelance portfolio" was enough. On the evisa site, of you are in/from Germany, you pick one of the three locations depending on the region in Germany
I just used a standard resume and changed "resume" to "freelance portfolio" and made clear that all entries were freelance/remote work. I didn't provide any contact info and as said I wasn't asked to provide anything else. I think your idea sounds excellent and will be accepted without issue.