If you want to do fondant icing, the Pettinice fondant you can get from the supermarket is DF, EF and NF. It's basically just sugar

You can make a buttercream with olivani instead of butter, or with kremelta, which actually works quite well in the summer because it won't melt in the heat like buttercream can. I really like the
wilton buttercream recipe which is half butter (but I use olivani) and half kremelta, and then sub rice milk for the milk. Its yum and lasts well in the heat.