Simon,
If it were me, and I was determined to use a 60 series tire, considering the fender interference problem, I'd use a 205/60-15 (24.7" tall). You gain nearly 1/2" of clearance, which should eliminate the problem. With a 215/60-15, you gain less than 1/4" of clearance, which might not be enough to solve Eugen's rubbing problem.