Bootloader for SAMD21xxxx ARM (Arduino Zero)

Hi All,

I am planning on making a custom Arduino compatible board using a SAMD21xxxx ARM microcontroller.

I am aware that the Arduino Zero uses the SAMD21G18A, however I was considering using something a little cheaper, perhaps the SAMD21G16A. I believe that the Arduino Zero uses a slightly modified version of a standard ATMEL bootloader (SAM-BA), so I was wondering if I could just install this bootloader onto the *21G16A and then burn sketches to it as if it were a Zero?

I'm assuming that it wont be quite this simple, but I would appreciate it if someone could give me an idea of how much work it will be, and what the process is to get a 21G16A working with the Arduino IDE. It would also be quite nice if I could get my custom Arduino to have it's own board name in the Boards list, under the tools menu.

Any help or advise would be appreciated.

Thanks in advance, -Steve