what board / processor options for the ATSM3X8E?

I ran out of room on my uno and purchased a due.

When I select "Board: Duemilanove or Diecimila" it show

ATmega 328 or atmega168 as processor options, which is incorrect.

My actual processor has ATSAM3X8E printed on it.

I select atmega168.

When I try to download I get insufficient memory.

Sketch uses 14,700 bytes (102%) of program storage space. Maximum is 14,336 bytes.
Global variables use 1,990 bytes (194%) of dynamic memory, leaving -966 bytes for local variables. Maximum is 1,024 bytes.

So I tried a different board option. But unless there are multiple processor options, I have no idea if what I select is the correct processor.

Stumped?

What is the correct option?

This is what I bought.
http://www.amazon.com/Arduino-Compatible-DUE-With-Cable/dp/B00NFSXTR0?ie=UTF8&psc=1&redirect=true&ref_=oh_aui_detailpage_o03_s00

Hello DivinerGregg,

You have to use any Arduino IDE 1.5.X or 1.6.x and select Arduino Due programming port.
Take a look at the following link:

Regards,

-p

The "Due" is entirely different from the "Duemilanove" (that'd be "two" and "2009", translated)
To see the Due in your boards menu, you'll first have to install the "Arduino SAM Boards" package with the "boards manager."

Thanks!!