I had the dreaded head gasket failure and right now it's apart in the garage with heads out getting machined. While it's apart what else should I attend to on the the block. I am already doing the timing belt, idlers, oil plate, water pump, and full gasket kit. I am just looking for any one's opoinon what they would do.

sounds like you got it covered.

 

Subaru only head gasket hopefully?

 

have the valves adjusted, probably already being done at the shop?

 

full timing belt job - pulleys and tensioner for sure.

 

outside of that, just the cam seals and reseal the oil pump.

It's a DOHC so I will have to the valve adjustment/shim my self with the cams in. What about resealing the oil pump, I've read to check the screws in the back but what about resealing it.

locktite the screws on the back.

reseal the oil pump body to the block with anaerobic sealant in a tube - available at any auto parts store, with the accompanying spray. the oil pump also has an oring and seal (which is also the crank seal), buy from Subaru or your favorite whatever joint.