i know hosausa.com has a variety of sizes, but i doubt you'd be able to share.
chunei are the one kind of carrier that i think would be a pain to pass back and forth between two people. it's a little fiddly to get it "just right" but once you do you can keep it set so you just throw it right on and it's soooo quick. but if you had to adjust it every time because someone else had been wearing it, it would be a real pain IMO. there's shoulders, waist and chest straps that need to be adjusted, and they're not like SSC adjustments with buckle and webbing that you give a little tug and it's there, more threading fabric through the buckles, which gives a super comfy fit once you get it where you want it, but it would drive me nuts to have to do that very often.
