buy a barrel chambered for 223 AI and screw it on your action. I see your located in Canada so I dont know all the regs and what not.
If you lived in the states, you could send your barreled action to pacnor, get a stainless super match barrel threaded and chambered to your caliber of choice, and true/square up your action for $610. The barrel is $310, the action truing is $300. Turn around time is around 3-4 months. Bout the cheapest, best way I would know how to do on a Rem action.
Even cheaper yet would be to build on a slavage action. All you would need is to buy the barrel ($310) and screw it on yourself as there is no truing up a savage action. You would need a few parts [beeep] to do this.
Pac Nor does have a "Rem Nut" now which is the same concept as the savage to where you can change barrels quickly/easily yourself with a set of no/go gauges. Think its like $65 or something.
PacNors seem to shoot pretty good from what I've read and seen first hand.