I was working with a mom this morning whose large (14.5 lb) two month old was really fussy in her pouch, too. We switched to a tummy to tummy carry in the same pouch, and it was like a new baby, she loved it so much! Two minutes after the position change, and she was sound asleep and mom was all smiles. (and the pouch almost seemed too big). LMK if you need tips on how to do this carry in a pouch. I think it should definitely be roomier for your chest, and no pressure on your poor ducts.
With such a big baby, you'd probably do well with a mei tai. It will distribute the weight across both shoulders, and the straps aren't against your chest, so I don't think you'd have to worry about your milk ducts. Most mei tais I know of are cotton -- I don't know if that counts as a wicking fabric or not. Sachi Carriers also makes a solarveil mei tai, which is pretty awesome. It's a breathable mesh fabric that somehow still provides UV protection. They're here: http://www.sachicarriers.com/catalog.php?category=14
With such a big baby, you'd probably do well with a mei tai. It will distribute the weight across both shoulders, and the straps aren't against your chest, so I don't think you'd have to worry about your milk ducts. Most mei tais I know of are cotton -- I don't know if that counts as a wicking fabric or not. Sachi Carriers also makes a solarveil mei tai, which is pretty awesome. It's a breathable mesh fabric that somehow still provides UV protection. They're here: http://www.sachicarriers.com/catalog.php?category=14
