Nobody has access to new 12.5" or 14" Remington barrels because of US State Dept restrictions. Your only bet would be to buy a used one. Prices seem to have come down recently, what with all the Grizzly's and HP9s on the market. Last one I saw in the EE was only $250, that's a far cry from the $400 they used to fetch a couple of years ago. Almost bought it myself but I couldn't justify it since I already have one.
So, to answer your question, Dlask is your only option, or buy a chinese gun, they're fantastic bang for your buck, you get an entire shotgun for about the same price that a Remington or Dlask barrel would cost you.