Hey...congrats on the S10! Oddly enough, I've also been looking at S10s as potential salt candidates, probably because of their "less-car-to-deal-with" appeal as a platform, although of course there's ALWAYS a lot more to deal with regardless of the car and class you choose. In any case, great idea to get the extended cab--it'll make getting a full-containment seat, cage and fire stuff in there at least a little easier.
Does that have the 2.2 motor or the V6? If it's the latter, you might consider rebuilding that instead of swapping it out for a bigger engine that'll be a PITA to squeeze into the little S10 engine bay (although race-only makes that task easier). Boosted and built, the 4.6 V6 can probably make upward of 400 hp...
Where are you located?