Catamaran design help

[rkpshenoy]

This is for all those who have prior knowledge of designing a passenger cat.
I have already done preliminary design of my catamaran design the way conventional ships are designed by following similar steps but for sticking to the required L/B , S/L ratios for catamarans. Having done that i saw that the lines plan i chose is inapplicable to my design. The CB of the hard chine hull form is far below the required value for the displacement calculated.Later i learnt from some other guy in discussion forum that my approach in fixing the dimensions itself is wrong.
If so plz tell me how to fix the main dimensions like planing length..., trim, lift required etc for catamarans.Also if you can suggest me any catamaran or a planing hull specific book it would be gr8.
Id let you know about the details of my project after anybody has replied.
Suggestions of all kinds are invited.