Great combination of flavors! I used a devil's food cake mix and it worked fine.
The only change I made was I upped the orange flavor in the frosting a lot. After adding the tablespoon of zest, the frosting just tasted like cream cheese to me, so I started to add more and more plus squeezed juice from the orange in there. In the end, I just about used all the zest from the orange and a few squeezes of the juice and the flavor was great to me and everyone who ate it thought so too.
The cake wasn't difficult to make but it was time consuming. However, that could be due to the changes I made with the frosting. But I thought it was well worth it.