Ingredients sound great, could even considering sprinkling the inside with some sort of seasoning, at the very least I always add fresh cracked black pepper. Shouldn't be a problem doing them the day before (took me 3 hours of prep yesterday before I did mine so wish I had) but if you decide to stuff it iwth and kind of greens like spinach then I would do it that stay simply because the moisture could cause the spinach to get a little more soggy and not hold up as well. Tofu would be good though (well not good) because it could soak up all those flavors, anyone tried tofu in a fattie yet? Soon I want to figure out how to make one completely out of fake meats and wrapped in fake veggie bacon and smoke for my Dad...Shhhh... he is a vegetarian.
Oh, also try to post pics Darwin, and good luck.