What barrel next?

I have a T/C Encore and am looking at getting another barrel. So far I have 15" 243 Win pistol, 15" 30-06 pistol, and a 24" rifle setup in 7mm-08. I am looking to add another barrel but really cannot make up my mind. My next barrel most likely will be used with iron sights. I wish I could get a .44 magnum rifle barrel but T/C does not make them any more and a custom barrel is a little out of my price range. One issue I have with .45-70 is that it cost twice as much to reload and I really dont plan on casting. So does anyone have any thoughts or input?

Barrel options:

-12" 44 mag pistol barrel
-15" 45-70 pistol barrel
-24" 45-70 rifle barrel

These look like fun:

http://www.gunbroker.com/Auction/ViewItem.aspx?Item=385730772
2-Encore pistol Barrels, 15" 204 & 22-250