If you d cut it down and have issues with enough stack height later, you can go with the Tange headsets. They make a cheap OEM HS with very low stack height (but no seals) and several others with varying stacks. The headsets mix and match well. The cheap HS (~$8) is actually a decent HS if you run a fender and pack the bearings with marine grease as well as being a good source of low stack non-bearing parts.

Ben