Help please.

I've ordered a Mud Cake from Woolies for my little mans Christening on Sunday. I plan to ice it, put white chocolate shards around the edge & write his name & the date on it.
Thing is, what Icing do you think is best for a Mud Cake. I can do butter cream no worries, but was thinking I should attempt a Ganache??? or could I use the Betty Crocker icing??? Anything that makes it easier for me?

What are your thoughts??