When it comes to tuning an R-9 I would use Macarri internal parts only.
When it comes to Airgun stocks I go to Steve Corcoran. The thing I like about his work is that it is simple, honest, and ergonomically correct for airguns. Once you hold one of his stocks you get the impression that he actually made that stock for himself. Also, words cannot describe the satisfaction one gets when shouldering one of his stocks with Steve's actual deep hand cut checkering that just grabs your hands when handling them.
These two matching stocks are on matching limited edition R-9's that are both .177 and .20 caliber. Keepers fer sure!