What kind of cake mix is best?

For my friend's 13th birthday party, my friend and I are making our first fondant cake! We've planned out all the fondant pieces, and have everything ready to go. Now, we run into our problem. We can't choose a kind of cake mix! Many of our friends say red velvet is the way to go. What do you guys think? Thank you so much! BTW It must be from a box (eg Betty Crocker) and it can't contain peanuts or treenuts as my friend is alergic