My daughter's getting married in about a month and I volunteered to make her cake. This cake has to be freakin' PERFECT. I need a fail safe recipe for good decorating icing. I live in florida (hot all the time) and it's hard to find a good buttercream that doesn't melt, unless I use the all veg shortening an 10x powdered sugar icing which ends up tasting like sugary grease. Any suggestions?