josephchrzempiec:
So next question is to make a HID device of any kind would need USB native port on it. Does it really need to be a teensy?
The board does not need to have native USB as it can emulate USB like the ATmega16U2/8U2 used on the UNO as the USB-serial converter does but IMO native USB is easier to work with from a hardware and firmware point of view.
You don't need to use a Teensy as there are many ways to skin a cat 
and to decide this you can maybe tell us how many keys your keyboard will have.