Wiimotes with Wiimotion plus require specific bluetooth dongles that support Toshiba Bluetooth stack due to MSBluetooth stack sucking; unless you're not using windows then you're fine.
Dolphin supports all first party wiimotes to my knowledge, and I've seen some third party remotes work, and some not. It's very simple to use real wiimotes and they work wonderfully in my experience. Motion Plus also works well; though sometimes it can be a pain in the ass to get some games to detect it being plugged in (in my experience, at least. Other people report no problems.)
Dolphin supports all first party wiimotes to my knowledge, and I've seen some third party remotes work, and some not. It's very simple to use real wiimotes and they work wonderfully in my experience. Motion Plus also works well; though sometimes it can be a pain in the ass to get some games to detect it being plugged in (in my experience, at least. Other people report no problems.)