is it ok if i use white fluffy icing on my simple wedding cake?

is it ok if i use white fluffy icing on my simple wedding cake?

it is 3 layer cake n my cake is moist chocolate cake.help asap pls
if white fluffy icing or 7 minute frosting,what would u suggest how will i decorate it?
what if ill use 7 minute frosting then put some powdered sugar in it so it will become royal icing to hold the cake.would that be ok ?is in it too sweet?

source: http://answers.yahoo.com/question/?qid=20080123190129AAApgEd