Concept make a 23', which doesn't include the platform.
There's also the new 24' Spectre, which I think may include the platform, since it's integrated.
Also the Donzi 23ZF.
I think the smallest current Baja CC is a 25'.
I know they're all bigger than 21'-22', but I can't think of any performance CC's that are smaller.
My next boat is probably going to be a CC too.