You could make up the extra Kahula with vodka and maybe a little extra coffee, I reckon.
But those molds make me apprehensive. What's wrong with a basic round mold? Seems to me like you want to run an olympic-time mile before you've mastered walking. I just feel a mold with fewer crevices would set you up for a better chance of success. You know how upset you'll be if it doesn't come out properly and looks like a pile of rubble. although I'm sure you'll be consoled by it being yummy tasting rubble.
And while I'm wearing the bad cop hat, how much is this cake going to end up costing?
I mean i know that it's a hobby rather than just groceries for the family, but hot damn that's going to be one expensive cake!