A source for barrels is the Savage 94 hammer gun.
I would advise trying the barrel first before buying the donor gun, but up to this point I haven't found a 94 barrel that didn't have a little extra metal so that it could be fitted to the 219 (or 220).
I have a 219 with 3 barrels at this point. The only difference is that the 219 has a snap fore end and the 94 is a screw on.
25-35 is on my list. Nice choice.
Good luck.

Tom

Carbonation without fermentation is tyranny