That looks like a normal rack that the poster bent out to clear the caliper.

Lots of companies make disc-compatible racks:
Topeak® Cycling Accessories ? Products - Racks
Racks « Products « Axiom Performance Gear
Racks

Could you flip the bottom brackets around so the single bolt is facing backwards, moving the whole rack forward? Or maybe drill an extra hole in the bottom bracket a little further back from the original hole, which would also bring the rack forward, and alleviating the stress on the center support?
In comparing the picture of the rack on the bike to Axiom's website it looks like you have the road version and not the disc compatible version.