For my mothers birthday tomorrow I plan to make a four layered southern devil's food cake, the recipe I am using, one that I have used before, goes really well with ganache, but my mother love cream cheese on her devils food cake, I was thinking of using the ganache between layers then coating the outside with a cream cheese frosting. I do not want to do that though if the flavors do not go well together, and I really do not want to make something that I won't use. 

All advice welcome, thank you!

Absolutely! The cream cheese frosting (mine anyway) isn't as sweet so I think it makes a great compliment.