The fork is designed to take as big as a 40mm tire with fenders... there's a huge gap between the crown and the rim.
With 28mm tires, I had to makeshift an extra long hanger for my front fender so there wasn't a huge gap between the tire and fender. I don't think you can get away with a standard reach caliper for that frame.

Considering the canti studs aren't removable, I think you should stick with the cantis. Tektro CR720's are the bomb.