Which Arduino do i buy?

because I don't see a spot on the Mega for a DIP compared with the other board.

What do you mean by DIP? DIP as a noun is used to describe a IC packaging type, meaning Dual Inline Package. Maybe you mean DIP socket that the standard Arduino uses for it's 168 or 328 processor? If so the Arduino Mega board uses a AVR mega1280 chip that is not avalible in a DIP package option.

Lefty