SCE Ready-To-Run (O-ringed) 0.043 G54B copper billet head gasket ordered. Being made to order, so got a bit over a week before it ships. $130, but it's re-usable.

Had a long talk with the tech, suggested NOT going thicker than stock on a naturally aspirated engine, and if I do turbo it down the road, this gasket will still work, albeit not as well as a slightly thicker one.