Stock part is: 20320PA011 (Both sides, same part, $80 each)
Subaru Dealers have it.
Here is one (my local dealer), yours may be cheaper:
http://www.subarupartsforyou.com/cp_...hp?partid=5704
Not sure what the koni's use for top mounts, if they use the stock ones, that is them.
Other option: K-Mac, Price $480 a pair + shipping
http://www.k-mac.com/pages/newprods/subaru/subaru.htm