This would have solved the issue of the Wraith in SG:A and the Ori in Stargate:Sg1 give them the origin coordinates to the Ori super gate. Let the two duke it out and than take on the winner. The Ori would have to go on the defensive, buying you time to find a solution in both galaxies. It would make for a cool alternative timeline RPG campaign: infiltrating into the war zone to find a Ancient/Ori/Pr-Wraith weapons left behind from when they were corporeal creatures. As for the Wraith, you could give them Sarcophagi technology. They do have deranged human "cultists" they could use the sarcophagi to regenerate for food. This would remove them as a threat if they win.