As far as the HP blocks go, if you're skeptical, I'd wait until he had them in stock and ready to ship before committing. He said they should have a good supply by the middle of the year. I have zero experience w/ them, I just got curious this morning and gave them a call.
I just listed one in the classified section, if anyone is interested.
Mike Beachel
I didn't write the rules of math nor create the laws of physics, I am just bound by them.