Rob i reckon you could get away with half the oil to be honest, next one i cook i will try it, but at the moment i have to many curries to eat LOL, Gee im gonna be stuffed! ;D
Ruby to right mate there are many foil size difference's, And they are finished dish's, Not just the base.
Here's the one's i use, Same size as a takeaway, hope it help's. length: 200mm width:100mm depth: 5omm.