Bubba's Foot (find them at http://www.bubbasfoot.com.au )
are stocking some awesome cold-weather options. You can find me talking about their soft and snuggly hoodies, but right now let's rave about their waterproof soft shell jacket.
This works for front, back AND tandem carries (and comes with the baby and toddler insert panels as standard).
It also features a zip in panel to cover the wearer's chest/throat, so you don't need to stuff a scarf in there (because hello potential baby suffocation hazard) and won't die of wind chill!
I particularly love the sleeves - they have a thumbless mitten sewn in to keep hands snuggly - not cold enough for that? you can simply tuck the extra up into the cuff.
Zips have some clever construction - like their own stiff baffle over the top - which makes it virtually impossible to get anything caught in the teeth of the zipper. Being highly accident prone, i think this is one of those really minor but awesome extras. The jacket would work perfectly well WITHOUT them, but it's quite a bit nicer with. The back panel closes with press studs and the same baffled zipper.
Panels gather at top and bottom for a very snug and well weatherproofed fit.
As for sizing, these are absolutely true to size - I wear an Australian size 10 and measure about 36-28-34. In a medium soft shell I have room to layer a hoodie or a thick cardi. Feel the need to browse your color options? Head to http://www.bubbasfoot.com.au and watch me on Facebook for a freebie!