Hey, CO, my old stomping grounds.
If you shop on line you can find the Axxis deluxe plus for just a bit more than OEM, lower dust, excellent performance hot or cold, wet or dry and the pad isn't so hard it will wear out your rotors faster.
If you change compounds dramatically, such as to the Akebono ceramics, conventional wisdom is that you should change the fronts and the rears. There is some discussion about this on the various forums; suffice it to say there is the potential for a safety issue and only you can decide whether the possibility of the risk is worth the few bucks you'd save (you can probably guess I would not...).
MB brakes are very, very well designed, so there is really no reason to replace the rotors with anything other than the OEM. All you'll do is spend money you could have spent on something else (like a MAF or window regulator). Order them, the brake paste and the sensors from autohausaz.com, free shipping, good service. If you go aftermarket on the pads you'll have to shop somewhere besides autohausaz, but for the OEM stuff they're usually pretty hard to beat.
Welcome to the forum (finally!), by the way.
Take care and enjoy the ride,
Greg