You might just want to shoot yourself now instead of later.

I'm doing a 1/6 Hetzer and it really is a great scale, but you're going to find some challenges along the way. For example, with my Hetzer I ended up completely replacing the drive system with better motors and chain drive. What kind of features are you planning for the King Tiger? I mean, besides the usual rotation and elevation and what-not. Are you going to put in a paintball cannon? Maybe a smoke and flash feature? Do you want barrel recoil? LED flash in the machine gun? What about sound? Smoke? Gotten that far in the planning yet?