Angueto
I have the SIG kit as well, it is certainly worth every $ you pay for. Keep in mind that this kit not a standard STA, but a STA Special. The most obvious difference is the covered front cockpit. IIRC, the original plane is still around somewhere in the US, although not in best shape :-(
The SIG kit is in the .60 range, I will power mine with a 91FS.

Good luck
Flo