Thank you all for your suggestions and advice so far!
The tuner I'm going to use is Kieth Fields from AWD Tuning near Dallas. I've sent my list to him with the same questions, and am waiting his return. I thought I would post this here so I could gather some more information without having to flood his inbox.
Ideally, I won't have to buy a new block, but just build my current one. My only worry was if the machinist would have to bore the cylinders to XXX.XX mm, that it would put the block at a significant risk. If so, I'd rather have the insurance of using a new block which would require such boring.