CY6 are a great set of rules and you should be quite happy playing them in 1/600 scale. What period of WWII or post-war will you be doing? Early war, Mid-war, Late-war or Post-war? I am gaming in 1/200 scale WWI using other rules right now but one of 2015’s projects is to begin playing WWII Early-war 1/300th scale aerial combat using CY6 rules. I wish you the best in your new project and please keep us posted on how it progresses.
Cheers and good gaming.