Classroom mic, MP3 player

A portable system that you can use in a classroom setup where your headmic is a compact unit with a small UHF or VHF transmitter which transmits to a standalone speaker placed anywhere in the classroom. Normal FM systems don't work that well (I find) as they pick up too many other transmitters around them especially if the other teachers around you are using the same FM system. You also have an MP3 player on your arm or palm that allows you to play songs when you need to. The MP3 player also plays through the mic's transmitter or a different transmitter to the same speaker. The speaker, MP3 player as well as the mic's transmitter should have lithium batteries inside so that they can be charged electrically or even through solar power if possible. They should be able to hold their charge long enough to last at least four to eight hours or a normal working day. It would be nice if the device that holds the MP3 player could also have effects built in that one can use with the headmic. Echo, reverb, helium-like effects, etc. can be a great help when trying to hold the attention of young (and even adult) students. I've tried using Bluetooth with a mic but unfortunately it has a delay when used with a mic. It is however perfect with a music player. Perhaps the transmitter and the Bluetooth can be used together through the same speaker. Currently, I already use a hardy self-designed headmic (more like an ear mic) which is attached to a transmitter that clips onto my belt. The headmic I would like is one that has the transmitter built in or at least attaches to a small unit that clips onto something close by like my collar.