Holy **** MKS touring pedals are wide. As you found out, it's generally not advisable to use such wide pedals on a fixed gear. The MKS Stream is a thinner version of the touring pedals. I would recommend you start there since you already know the larger version works for you. I've used both and found the Stream to be fine on a road conversion with a low bottom bracket, no strike issues.

http://www.yellowjersey.org/MKS_TECH.JPG