Can anyone recommend a shop that really know Subaru engines? I have a valve(?) noise and an oil leak that need to be properly diagnosed and repaired by someone with reasonable labor rates. I'm in Falls Church City but I would drive a bit to really good.shop.

sometimes a google search gives a lot of hits: 

http://forums.nasioc.com/forums/showthread.php?t=1820027

 

there's a few DC/Balt area guys on subaruoutback.org that i think have recently answered your question too. 

Bill Haas of Haas Automotive in Manassas has worked on Subaru's for many years (worked as a Subaru mechanic and has had his own shop for a number of years). My parents have taken their 2000 Outback to him since it was new.