Any suggestion or will a plain butter cream be fine

Chocolate butter creams sounds good.

Where do you find Butter Pecan cake Mix? I hear there is a Coconut Cake mix too...can't find any of those interesting flavors! Darn!

I get it at my local Walmart. They have the coconut, too.

I usually make Pecan Pie Cake with mine, that doesn't have a frosting. Maybe something like a maple bc would be good, or caramel bc.

I picked mine up at the local grocery store Food lion.

If you mean in the cake mix I add chopped pecans and kahlua....for buttercream i use hazelnut flavor or kahlua(sp?)