Build a mini 230-250 quad based on the knuckle or possibly with a smaller center plate, but it shouldn't matter. Print motor mounts for the as based on the v-tail motor mounts, but with 30 degree angle instead of 45, possibly add some legs to the front for stable take off. And there's the racer quad they'd build.
However the problem isn't the build. Its that whoever gets the biggest motors, smaller battery and shortest flight time wins :/ unless you standardize the electronics, or demand minimum flight time or something and a price ceiling.