Alternative to Flip wraps?

I have a large stash of Flips that I used as DS's nursery nappies. I was hoping to use them again for my twins when they start nursery in September, but I'm having major problems with wing droop as the girls are both very slim.

Can anyone recommend an alternative wrap with side snaps that would work with cotton flip inserts?

Yes-gen y are very good. They do a universal one with side snaps which has a layer at the top and bottom for inserts but they're normally cotton outer whereas flips are 'naked pul' without that cotton covering x

(i'm selling some gen-y's btw on classifieds actually)