Your also forgetting the hub flange distance from center. It is probably much less on one side than the other, hence the dish, even with same length spokes (assuming the same cross pattern both sides).

You could probably use 293/294, 294/294, or 293/295.

If you are using the same spoke type on both sides, then make your like easy and use 294s.

Sapim 14 DBs can be had for .40 from danscomp.com FWIW.