I want to make a WASC cake for my son's first birthday (my second time doing wasc) but I am wondering what kind of icing I should use with it this time. I really want to try cream cheese icing (never done it before) does it go well together?

Other question: I want to do the flowers for the cake in advance. Can I do it with the cream cheese icing? How long in advance can I make it and how should I store it?

Thank you so much for looking and hopefully you can help me