For a larger/heavier baby/toddler you could look at a getting a CatBirdBaby Mei Tai with a support belt (also made by the same company). I've also heard people comment favourably on Babyhawks for toddlers (they also made a toddlerhawk which has a taller body and head-rest). You might also want to google the Australian maker "Walleroo", I *think* she sells on Ozebaby but not sure, as a WAHM her stockings are snapped up quickly, but they are great mei tais and very beautiful.

The keys to a good toddler mei tai is a supportive, longer body and well padded waistband. A HAB or stretchy wrap will not be overly supportive for a toddler as it has too much give in it. If you like using wraps, then a woven wrap could also be something that you might consider. Storchenweige, Girasol and Didymos wraps are supportive (and slightly heavier weight) for toddlers, if you live in a hotter climate Vatanai wraps are breathable and thin yet very supportive.

Alternatively, if you google Baby Carriers Downunder and join the google group you will be able to get more info from people who have more experience with carrying toddlers. My 11 month old is 11 kg and I mostly use mei tais, a DIY BBO (Ball Baby Overall), and a custom made MT that was converted from a Didymos wrap.