Hey Mic,
We have been using our old 3/4 thermarests for the boys which works out well for the moment mostly car camping... I 've also been thinking about an alternate so let us know what you come up with

I spent many an hour trying to find them a sleeping bag. I quite liked the MEC ones
http://www.mec.ca/Products/product_deta ... 4442624488but in the end thought they might be a bit short as my oldest is 7.
I also liked the Goat 20 which is a synthetic but couldn't get it when I wanted it....
In the end I bought them 600 fill down Sierra Designs Diamond Springs bags rated to 30 degrees- got the womens as they are shorter (don't tell the boys

). Nice bags, weigh about 1kg and were on sale at campsaver a while back. Haven't used them in the cold yet but look nice enough. Only thing is the zips are a bit fiddly for little hands.
this is the 15 degree version
http://www.campsaver.com/Diamond-Spring ... g-600-DownMacpac looks nice too
Good luck
Lizzy
Lizzy