you could substitute the chunky's for the packs with 4 sticks in them. They'd probably be about the same. I'd be inclined to just roll the rolling pin over them while applying pressure though because they're not quite as ummm...sturdy as the chunky ones.
I'd probably get a couple of extras also because the chocolate content is not as high in the fingers which means you might have trouble with the base. Either that or just melt a bit of plain milk chocolate along with the ones you melt for the base.