Offshore CAT help

[Catman]

I am designing a scale Class 1 offshore cat inspired by MPYD designs.

I have been using Carlson Hull Designer to design the sponsons to give me an acceptable center of bouyancy. Seems to be working well so far, however it doesnt plot out the patterns for me.
My effort is to produce a 58" Class1 CAT with dual zenoah G-23 engines(3.2 HP), surface planning drives an 75mm props. My main concern is the stepping of the hull bottoms and the tunnel shape. And the room to accomodate the two engines without changing the waterline and displacement characteristics.

I would appreciate if someone with technical knowledge could point me in the right direction. I can e-mail my preliminary CAD designs and Carlson Hull file if someone is interested in helping.
This link may give you a better idea of what I am trying to achieve: http://www.swissmodelpowerboatteam.ch/

Thanks!!!