Async Multiplayer Game

I made a pass and play game. I was to add online multiplayer. Normally I wouldn't care about the login with this type of system, but I will add the ability to purchase skins. So I was wondering what people of found is the "best"/easiest way to implement this type of functionality. I made a poll below to get opinions and in case anyone was wondering I was planning to release to the XBone, so the PSN is not an option.
Thanks,
Christopher Wang
http://www.steamfistinnovations.com