Hmm, idk if what I know is correct or not, currently the closest you can find is Logitech K800, which is a membrane keyboard, not mechanical, but is backlit, full size and wireless.

I can't seem to find any other offerings at this moment, most are in TKL layout. Even TKL mechanical offerings for wireless is quite limited.

Mechanical Based? Or just normal keyboard...?
If normal keyboards, you're in a wrong thread.

Cableless/Bluetooth/Wifi Mechanical Keyboard, I think so far, it's Filco Convertible Keyboard.