Ranger,
I think if you buy a factory barrel and then pay to cut if down, you are pretty much in the price range of a custom barrel that you can have made to any length you want anyway. I did just about exactly what you are planning. I wanted a nice short, compact, but tack driver rifle with enough power for most all big game hunting. I got a 20" .308 T/C Custom Shop barrel from Ed's Contenders and I also mounted the "bantam" stock on my Encore. I think the 20" length is a bit more efficient for the .308 and with the singleshot action, the rifle is inherently short anyway. I think most American rifle stocks are longer (LOP) than necessary and the "Bantam" Encore stock is just about a perfect compromise for length, portability, and a good hold. I am 5' 11" - pretty average size, and I get along fine with most factory stocks, but get along real well when about an inch shorter as well, and I think you can get a better hold and cheek weld with a slightly shorter stock - especially with a heavier hunting coat on.
I belive I paid $255 for my barrel from Ed's TCs. I just measured and weighed my rifle - it is 33.5" overall, weighs 7# - 3 oz. with scope and Millett rings. LOP is 13.75 inches. The scope is a 4X Redfield LPWF compact. With Hornady Custom 150 gr. ammo I get MOA accuracy. Overall, I think it is one very compact, nicely balanced, and effective rifle. I did have a trigger job done on it from SSK also. BY comparison, I just weighed and measured my Ruger 77 MkII .308 International. It has the 18" barrel and the overal length is 38.25", weighs 7#5 oz. with a 2.5X Leupold compact scope. So my Encore is about 5" shorter with 2" more barrel. Well good luck with your project and if you go with an 18.5" barrel, you will really have a handy, compact, rifle. I wish I knew how to post pictures, I would put one up of mine. I really like it. Good shootin"