And don't be tempted to use monohull design principals, they often don't apply to cats.
I've already done what you are trying to do with my '430' but in glass, not plywood so it may not be possible to achieve the same result. I don't have plans for a wood version.
You might like to take a look at a small video someone shot at a regatta I did a couple of w/ends ago. Takes a while to load though
http://boatvids.netfirms.com/
Bern