Milan shouldn't have much issue. I recently added it to my list, I like it a lot.
Milan DominicMilan ChristopherMilan GregoryMilan RileyMilan Theodore
Dejan and
Jovan might have more difficulty, since English-speaking countries don't often make a J into a Y sound.
Dejan could be spelled
Dion though to make pronounciation easier.
My class is about to end. If you want more MN ideas, I can post them when I get home.