Thanks everyone for your valuable comments, they are much appreciated!
Here is another sketch with the collected informations for anybody to fall back on when designing your Race board.
@Bradn: Looking good, I think 55cm is the way to go. This version has 43L too.
Regarding the bottom edges I was going for sharp edges on my first board, thinking I need them to "grip" for extra upwind abillity. After I spend the last 10 sessions learning to foil I quickly realised this is not the case, in fact it's producting spray and catches the edge occasionally.
The chamfered edges will prevend this and I believe they are more forgiving on high speed touch downs. An a last note I think the edge grip on a foilboard is not that important as there is not much leeward drift (mast) and it's pivoting point is the tail (mast); correct me if I'm wrong!!!
Whats your experience with fast bottom contours (concave)?
Going to start shaping next week.
Good winds from Perth's late winter.