cuddy cabin i/b to c/c o/b conversion

I recently have been looking at tackling a conversion of a 23-25 cuddy cabin to a center console. I have two concerns at this point, both dealing with weight distribution and the intended plain of the hull...

1. The center console will be shifted aft from the origional forward starboard side helm.

2. I will be installing a bracket to harbor twin 150 o/b.

How much will each of these affect the intended plain of the vessel, and is there a formula or secret to determining the length of the bracket and distance of the console to the transom. Any help would be greatly appreciated.