^^; That's pretty much what I was going to recommend. Ben Nye's Clown White is awesome. I prefer the cream, but ya... You really should apply it with a makeup sponge. Then you have to set it with powder, but I guess it dosn't really matter, as long as the powder is white. I've even used baby powder before in a pinch, but it's not quite as white as you might think it is ._.; But hey, Ben Nye ALSO sells a white setting powder for his makeup, so that would probably be ideal ^^;;
But if SlyAngel is trying to go more for just the unearthly pale look, then Kaede's suggestion of Manic Panic's white foundation and powder is probably better. Those won't give the opaque appearance needed for some of Mana's more dramatic makeup looks, but will certainly whiten your skin quite a bit...