As far as extra barrels are concerned, long ago I figured out that searching for another SO is the way to go. A mismatched second set of barrels is not a guarantee of a good return of your investment at resale. Personally, the simplest solution to the desire for an open bored barrel is the installation of a set of Briley Ultralite 20 gauge tubes.
Quality advice, I just sold an SO4 that was in excellent condition that had a set of ASE 90 barrels fitted to it, people acted like that gun had swine flu!!!
Short story, you will never be able to get your money out of it if you invest in another set of barrels, if you can find any for that matter.
Keep looking around for another gun or you can have choke tubes done on your S2, you will experience less value loss at the time you want to sell than you would if had invested in another set of tubes.
H&H
