I'm not convinced there is a need for Tiger 2, and voted accordingly. I don't think it is anywhere near as well known as Tiger 1, T-34 or Sherman.
However, if you are set on including both turrets with a Tiger 2, what about an optional approach. Would it be possible to make the hull side and upper glacis plates separate components and double sided, with all the relevant details moulded onto them on each side, except that one side has zimmerit and the other doesn't. Make one turret with and one without (I think the flat fronted turret, I keep forgetting which manufacturer that is, had zimmerit more than the rounded one. Though I could be wrong, don't have my references to hand) and people can choose whether they want to build with Zim or without.
Double siding the parts would of course take up no extra space on the sprue compared with separating the parts anyway.