Chris,
you know we are always experimenting with new stuff. many teams in Europe have tried those carbon blocks, but are not really convinced because there is no real advantage (other than that the dealer has a better turnover).
The harken blocks have avery similar performance.
But, if you insist: Take the 57mm for the bottom and the 40 mm on the top, and tie the top blocks to the boom which allows more rakes. But then we have to turn over to the rudder discussion...

Fritz