In response to your question about compression, that should be completely safe in the hands of a good tuner.

I have no first hand experience with thin head gaskets, I've always tried to stay OEM in that dept.

Personally, I would explore all other possible options to raise compression, and use a 2 layer as a last resort. You can use flat faced valves, slightly mill the head, block, or both. Hell, a resurface might give you the bump your looking for.

Take more pics and post them as it comes together! I'm kicking myself for not documenting my build better, would have saved a lot of headaches.