One approach I have seen to address disks on tapered forks is to use a "willits" style disk tab that extends a good 6"+ above the upper mounting bolt, so the twisting force of the caliper is distributed along a much longer section of the fork, and the long tab itself adds some stiffness in axis needed. See these;
http://www.paragonmachineworks.com/c...ion&key=BK2009
http://ifbikesblog.blogspot.com/2009...disc-tabs.html

I would at minimum use the tandem CS, but since the Nova crown takes a ovalized 25.4 tube, you could also just start with a non-tapered 1" diameter 4130 tube of suitable wall thickness for the disk side, would be much stiffer in vicinity of the disk mount than a tapered leg.