You'll be fine no matter if its pre or post 2k...I used to have a 2004 cocker that I ran on a 20 oz. I also had a 2000 sniper that i ran off of a 3.5oz The Cocker/co2 hype was created by uneducated little fools when the LP craze came about. You wont be able to reliably run the cocker at Low pressure with co2 but who cares.
As far as a sniper goes you'll definatly be fine as long as you dont plan to run the gun off of 12 grams. You will the have to start worrying about devolumizing and springing.
"I wish simply to be a decent person, yet I will always fear the retards" -Brian Hindt(geech) MCB Moderator Kidney Machine