I make sugar figures out of 50% fondant and 50% modeling chocolate and I have some pieces that are still going strong after several years and thru all seasons.
The Garden Baker
If I were going to be making simple figures, I would use gum paste or fondant with a tylose added, so they will dry nice and hard. You will have to work quickly with either of these mediums, but they will hold up well to heat.
Sugar Sugar by SSmiley
