Opinion on prefold sizes, please?

EJensify

Purchasing my cloth-eez prefolds tonight...and am wondering about their sizes.

Their NB orange edge says they'll fit infants 5-10 lbs...well, I make big babies. My DD was 9lbs3oz and we're working on #2 now, and he's a boy...both of which are commonly larger, right? 

My question is this:

Is it reasonable to assume that I could by size small yellow edge cloth-eez prefolds and use them on a 9lb baby for a few weeks? ...or do I need to purchase two to three dozen orange edge for those couple of weeks?