Hi Jean,
Hammer and Phoenix are full on racing fins (have not tried, but just looking at the specs/where they fit into the respective ranges). They will work on the Blast if your goal is speed/power. If you just want something a bit more performance then probably the Dragon is better, although I have never tried these against our own fins. For your weight 40cm could be ok, depends a bit on sail size and your skill level.
I know the in the French Market the Blast owners who like to go a bit faster, esp south of France, like the Select fins - S1? Those look fairly similar to the fins in terms of rake you mentioned above (Hammer and Phoenix, but I think the Tectonics might be a touch too racy?)