Hi Rome,
I use a Topeak MTX - A type rack on my Vk2. It has 700 x 38c tires and I have no clearance problems.
http://www.rei.com/product/697096
There are 3 types of MTX racks; the A-type is listed as "small".
It mounts easier if you substitute a 40mm M6 bolt in place of the quick release. The QR tends to interfere with the Sofrider seat back rails. The bolt allows you to get an open-end wrench on it from the side.
I've also used a basic Performance bike rack on it when it had 26" tires, and I had no interference there, either.
Best,
Doug