Top for me would be a velocity aileron which is a 28mm deep, 19mm internal width rim so it pairs nicely with a 25c tire, alloy nipples, pillar wing21 spokes with a chris king r45 disc hub, 28h rear, could go 24h front. You don't specify disc vs rim but I'd assume a new build to be disc. The wing21 spokes are 2.2 at the hub so an all day go anywhere wheel but with a lighter weight aero profile so good for speed, and kings are light and fast, and on steep downhills will coast as fast as you want to go. Not a prebuilt but as lock solid as any and should be fairly light.