Is is the nappy or the wrap you're looking for? They do a Thirsties Duo wrap and Thirsties Duo nappy, I think it's a pocket nappy. And what size? Size 1 is 6-18lbs (although I have heard they don't actually last that long) and Size 2 is 18-40lbs.
I'll keep an eye out on CNT for you, there have been a few of both types come up recently.