GK Slicks
I have the exact same bike. I have been riding on Gravel King Slicks, 650x42mm. Wide enough for comfort but still roll very fast on the pavement. I can just about keep up the same pace as my Cannondale Synapse that are 700x28mm. Tubeless on at the 650's and tubes with the 700c. That Salsa is a good little bike. I've been very happy with it.