Hey bioprof. We use Long Hammock barrels in our Chambers fowler kits (PA and English). Riley makes a great smoothbore for us, and even a few rifled ones. Give him a buzz and see what he can do for you. (352) 748-7373
As for Rice, I've talked him into keeping the straights, but only in the match grades for competition shooting. So, it's not that he won't be making any more straights, it's just that they will be considered special order and may take a lot longer to get to you. He will be making them in 1", 1 1/16" and 1 1/8" all 44" long in calibers 40, 45, 50, and 54.
Hope this helps!