For the octo, why not just get HOG 2nd stage? I persoanlly think HOG classic 2nd is better than 212. 212 is almost entirely plastic. HOG class 2nd has metal barrel.
The extra 212 was only $100 and now, if I have any issue when traveling (e.g. in the Caribbean), I don't have to worry about not being able to troubleshoot a problem because I can't find someone who knows/has parts for Hollis and HOG (especially HOG).
Also, I did ask the guy (who exhibited a lot of detailed knowledge about regs and is an experienced Tech diver) about metal barrel vs plastic barrel. I had read something here on SB that left me with the understanding that a metal barrel is better for cold water. He said that it's the opposite. He said a plastic barrel is better for cold water. But, he said that only matters in really cold water. Not the "cold" water I'd be diving in around here (i.e. MAYBE down into the upper 40s).
Anyway, it's a done deal, now. I'm a new diver and this is my first reg set. I think it will serve me well for a long time. And the price was great.