I use a Kaffenback for my rain bike. Canti and V-brake studs are the same standard distance on all modern frames.
Those V-brakes have travel agents on them to adapt to the STI levers. I use mini v-brakes ( TEKTRO 926AL ) without the travel agents and STI levers. Mini v-brakes are just long enough to use with fenders if your tires are not larger then 25mm width.