RE: retrofit kit for start - eliminate clipperbox 'hump' ?
I would call or email Trident Sports in No. Vancouver, BC (The US and Canadian Distributor) and ask if they have any of the kits in stock, or can order one for you.
Failing that, I can suggest how to remove the "hump" and cut down the Clipper box center board so that you have a flat deck.
I did this "modification" to a couple of my boards before I received the retro fit centerboards and the new thinner CB cassette cover.
Hope this helps,