Hi Juan, not the team here, but pretty easy question to answer
In short, no. Your S11 57cm is way to big. If you want to stick with Select try the following combo's:
One fin only: S12 or V-Max 49 for 90kg+ rider
S12 or V-Max 47cm for under 90kg-.rider
Two fins: V-Max 47cm and S12 51cm for 90kg+ rider
V-Max 47cm and 51cm for under 90kg- rider.
The S12 is more powerfull than last years S10, but not as powerfull as the S11. The V-max is not as powerfull as the S12, but potentially faster shape.
Or try F-Hot fins. I am 100kg and using 52cm and 48cm on my iS137. I am about to order a 45cm as well for maxed -out days. These fins are the new trend shape like IFJU, Carpenter and Z Fins but cost much less (similar money to select fins). They also give very similar performance and I think you will see these fins alot more next year.
A few weeks ago, a UK PWA racer (no names, but he finished top 10 overall. Big clue) tested the F-Hot back to back with Z-Fins at Weymouth and concluded that the performed the same.
Just my 2 cents worth