Any of your oil finishes make a great finish. They require a little care to get them right, but when it comes to appearance the only thing better in my opinion is shellac, which isn't too good for outdoors.
Poly definitely is a more durable finish, and has it's places, but you won't go wrong with oil based finish. Unless you see your bow really getting abused, I'd go with the oil based finish, there are a lot of them to choose from but they are all essentially the same when it comes down to it, just different additives and varnish blends.
Tru Oil is a oil finish, just modified so it dries real fast, and I know a lot of gunsmiths use it on the stocks. If you think about the environments guns are taken into, it will give you an idea of how durable an oil finish can be.
Something else to consider, you can't really repair poly finishes, oil based finishes on the other hand aren't difficult at all to repair a small area, with poly you end up stripping the whole thing.