2001 H-6 - 150K service - Suggestions?

Hi all. My wife has an '01 Outback H-6, and I'm going to have our mechanic do some major maintenance on the engine.

Since it uses a timing chain, there is no belt that needs changing. So that's out.

There's definitely some kind of slow oil leak, so my plan is to have him pull the engine and replace all the gaskets. What would I need?

- Rear main seal

- Valve gaskets

- Head gaskets

- Missing anything??

Water pump?

Sensors?

I just had the plugs done, so those are good (OEM NGK platinums). I also just swapped out all four rotors and pads.

After this is done, I'll be replacing the stock suspension with some new OEM springs, and KYB GR2 struts:

Suspension Products for Subaru Outback LL Bean Wgn 2001

Thanks, I appreciate it.