I ddin't coment on your post here, as I have no experience on the S-Type 93.
But looking at what CC and jmunkKi have posted, I agree completely.
Juri (Munkki) has been at this along time, and if he likes his ST-93 setup, I
would take his advice. His skills may be different than yours, so watch out, that little board may "take off" and go alot faster than you really want until you get yourself dialed in on haw fast it can be.
As Crazy Chemical suggests, tuning small boards is a very individual thing, so you need
as much time on the water as possible to figure out what makes this little board really "sweet" for you, at your sailor weight, in your conditions, and with your rigs.
Start out with the mast foot pretty far back and sail the board well powered up (as Juri suggests) and then find your own individual sweet spot for the mast foot, and try a few different fins if you can.
At some point you will get everything balanced and sailing the ST-93 will become pretty much effortless.
Hope this helps,