I'd go 32h 3x and you'd never have an issue with stiffness. I'm a weight weenie at heart and will admit to you how little the 4 extra spokes matter in terms of weight and how essential they are in terms of stiffness.
It is literally less than a 25 gram difference between 28h and 32h.
And it's track cycling... Weight pretty much doesn't matter, let alone a measly 25 grams.
Aero drag does though, so less spokes the better. Shorter spokes are better so high flange (especially at your weight) will allow that. Though honestly why not a disc rear? Mechanic watt advantage offsets weight and you can get a lot of older, stiff Zipps for cheap.
The radial lacing on the front...on a 60...I dunno. At 154 I did my pursuits and team sprint on a 90 with 20 spokes and low flange radial. Add 40 pounds and lengthen the spokes and I could see that getting a bit squirmy.
Tons of high flange hubs out there these days for cheap.
I really hate the feeling of letting the power off 1/10000000 of a watt just because you think about the risks of breaking something. I guess I'll go with 32h 3X / high flange just to be sure. I just don't want to carry useless weight/drag.
With deep rims, you can get away with fewer spokes - even with a low spoke count, where the spokes meet the rim (at a smaller "internal diameter"), the spokes are still close enough together to be quite stiff. Add a high flange hub, and the short spoke length means that once again, you've got the makings of a stiff wheel.