Angel food will not hold up under the weight of fondant. It has too much air in it. You might check out the suggestion that Teresa has... I am diabetic but I do not bake that way!
I know Buddy on the Cake Boss uses sponge cake all the time so I know it will hold up to carving... I never make sponge cake so I can't really speak for the sugar content in it. I just know with my diabetes I just watch my intake... but I never bake that way.... my cakes are loaded with all the good stuff.