Eureka! I've got it! You need to make two cheesecakes and stack 'em. Let me explain. I tried and experiment last year that produced a wonderful cheesecake filling but was altogether a flop. I made my usual cheesecaked filling in my 10-inch sprinform pan. But it was crustless. I did it by lining the pan, both bottom and sides, with lightly greased parchment paper. As the custard cooked, do to the protiens in the batter, it shrunk inward just slightly. I had pre-baked a graham cracker crust in the same pan and gently removed it before hand. When I removed the custard, it fit perfectly into the pre-made crust. What ruined my recipe is that I half filled the crust with a ganache and chilled it. I then placed the custard on top. I expected it to be perfect. The problem was that when the cheesecake was cut into, the ganache was properly liquified and ran all over the place. But the technique is still sound. Build you crust first and pre-bake it. Then bake the two cheesecakes in your two different sized, parchment-paper-lined pans. Then, when the filling is cooked through and cooled completely, stack them into the crust. You will have your enormously tall cheesecake. It should be spectacular. But make sure the recipe you use provides sufficient body for you to handle the crustless filling. If you want, I can post my recipe.
Seeeeeeya; Goodweed of the North (And the Goodweed has nothing to do with illegal substances. I was the kid that never grew like a bad weed, hence my pseaudonym).