Very easy for the Scout. Send the barrel to the gunsmith of your choice and have the breech plug installed. I favor the Gen2 system that Encore50A mentioned. I have 2 of those plugs in break aciton 45's and they work flawlessly, the plugs and modules are available from ArrowHead Sporting Goods, I'm not sure if he does the conversions on the Scout though, I had Bestill on this site do mine.
The Ultra-Lite would be a fine rifle but I would get it in a fast twist 45 cal., if that cal. is legal in your state and you plan on hunting with it. But, you would be limited on types of powder that could be shot, black powder and black powder substitutes only, and the bare primer ignition system may or may not leak, if left as a factory rifle.