That is quite the change in discipline! Have you thought about trying some WP lessons or possibly a lease horse to make sure this is something you will still enjoy? I adore WP, but it's not for everyone. I'd hate for you to replace your barrel horse and then realize it's not for you. Adding in some trail, horsemanship & western riding patterns may give you enough fun stuff to keep you busy. And you can still lope the barrels for fun, if you wish!
That said, I'd personally aim for a finished, well-hauled mount, as the potential of erratic behavior on a younger, less experienced prospect could cause issues with your back.
If you wish to show, find out what wins in your particular circuit - looks, size, movement, bloodlines, etc. - and go from there. Good luck!