I do a lot of road-racing(upto 3 hours any given weekend driving like a bat out of hell with no care) and shenaniganry, so my only priority is durability to my ability to dish it out.
The budget is around 15-17K (and set aside funds just in case of overrun).

I have a bone stock LS6, and ideally, I'd like to keep it as a core just in case something goes awry(either just a few parts, or a complete swap).
What engine and size would you go with? LS2, L92, or build on another an LS6/1, etc, etc?
What internals have you had good luck with?

As for the boost part:
I'm digging the STS setup, or a system that is overbuilt is not a bad thing either.
Boost levels, my only big thing is that I have the ability to have that thing run rich and at low boost levels for temp maintenance(I only req. 450-500whp when I'm at the track). Street it can run high all day long.
What's your take on this?

Driveline is weaklinked at the transmission. I'd rather that thing blow guts than the other parts.

Fire away at suggestions, I'm open to many many ideas, but I've got 0 experience with tweaking naturally aspirated engines to go boost. Is this a conceivable build or am I lowballing the number?

 

Have you checked out APS? http://www.airpowersystems.com.au/corvette/c5.htm