I need to do this cake in all buttercream.  It looks like its fondant but the client doesnt eat fondant and feels its a waste of her dollar.  

>How do you get aqua icing...?

>Also what are the spacer pieces between each tier of cake...? 

There is a Americolor mixing chart on here some where that may have aqua on it.

Those are cake spacers covered with ribbons I think, these links might help.

http://cakecentral.com/t/671319/stacking-cakes-with-styrafoam-spacers

http://cakecentral.com/newsearch?search=cake+spacers+&type=61

Hth

*http://cakecentral.com/t/589750/heres-a-mixing-color-chart