I can’t find the existing hub dimensions of the Zipp hubs so I’d say anything that has a wider hub flange diameter. The Industry Nine road hubs seem to have a 59mm drive side flange, so that could be a good option. Otherwise the MI5 hub from White Industries could also work with 55mm on both sides.
If the Zipps are laced 1x drive side and radial non drive side, going to a 2x drive and non drive side with CX-Rays would be a meaningful improvement when taking in combination.
We aren’t talking about a massive improvement here, but it could be a few percent which could prevent the rub at a lower all in cost.