You'd want to get a good recessive first for a couple reasons.
1) Anything you breed to her will be het clown, and you could possibly breed them back to mom the following year, opposed to breeding a male to any female that doesn't have the clown gene, then raising females for 2-3 years to breed them. 3 years is longer than 2 years =p.
2) As you stated, males mature much quicker. As another poster stated, it's 1 less mouth to feed while you raise your female, and males will slowly drop in price.
Big female recessives are sooooooo valuable! Especially a clown!
Something to note, Clowns vary quite a bit. You can hatch reduced clowns and busy clowns from any clown, but there ARE some lines of genetic reduced pattern clowns, and various other types. The genetic variations of clowns are typically a bit more expensive. Any clown is good for me since they vary so much
.