I'm going to make a bunco dice cake for a night out with the girls playing Bunco. This is my first cake like that, but I want to WOW everyone and hope that I can drum up some business.

I was thinking of:

Lemon Cake (WASC)
Raspberry Mousse Filling
White Chocolate Ganache Icing
MMF Fondant on top of entire cake (although I'm not so sure I will be able to cover a square cake, never attempted before. If I were to use a buttercream should I use just a vanilla buttercream or...)

Does that sound yummy or too much?

Yep that sounds very yummy!
I do believe if you go to you tube there is tutorial there for covering a square cake with fondant.

That does sound good. I just did a lemon cake with strawberry filling and vanilla buttercream. I didn't know how it was going to taste, but it did go over really well. I didn't want lemon buttercream because I thought that would be too much, so I did the vanilla. I made the amazing lemon cake posted in the recipe section. Here is the link:

http://www.cakecentral.com/cake_recipe-7371-AMAZING-Lemon-Cake-from-a-Mix.html

Good luck!

I have 2 cakes to do this month and both are Lemon w/ Raspberry filling and French vanilla BC ..

One of them is individual mini cakes shaped like Bunco dice..

I think The Lemon Raspberry combo is becoming quite popular..