As long as the back is good, i.e., lightproof the 220 should be fine. Paper backing on 120 is just wasted space and bulk. 220 film is also held flatter in magazine, which should result in sharper pictures at large fstops.

Do a test of your magazine in bright sunlight before you trust it. I had a 220 back for an RZ that often gave me trouble. It wasn't the films problem, it was the back.
Take care,