I see that you aren't interested in Ruger off the shelf; as one of the other posters said if you did go Ruger off the shelf then the Target model with the heavy barrel would be your best choice.
I'm making the assumption here that you are going to be using an optic, so if you don't want Ruger than a DAR with an integral rail is a great way to go. I prefer the heavier bull barrels with target chambers but they are heavier and tend to be front heavy. If you are weight sensitive maybe a lighter barrel for off hand might be better for you but it's a preference thing. I shoot a DAR with a KIDD bull barrel exclusively off hand in our local silhouette shoots and I don't mind it but others have picked it up and thought it was too heavy.
I'm making the assumption here that you are going to be using an optic, so if you don't want Ruger than a DAR with an integral rail is a great way to go. I prefer the heavier bull barrels with target chambers but they are heavier and tend to be front heavy. If you are weight sensitive maybe a lighter barrel for off hand might be better for you but it's a preference thing. I shoot a DAR with a KIDD bull barrel exclusively off hand in our local silhouette shoots and I don't mind it but others have picked it up and thought it was too heavy.