RE: Another game of pick-a-sling...
I have read that the adjustable pouches can do that range, but the fleece pouch may not work in that climate.
The Wilkinet is a Bjorn like carrier that is supposed to be far superior.
http://www.wilkinet.co.uk/
As far as ring slings go, I personally prefer the Maya Wrap. The Zolo sling is also a very nice sling, but perhaps a bit pricey for some. Some consider the Zolo to be THE ring sling, but others (including me) find other ring slings just as comfy. The Maya fabric would work really well for them in that climate.
Another to consider would be a sling from TaylorMadeTreasures.com. She has come in a light cotton that are supposed to be very nice.
HTH,
Beth, mom to older DD (8/01) and younger DD (10/06) and always missing Leah (4/22 - 5/1/05)