Ed,

Been busy here lately, so I have not had a chance to jump in on this one.  As others have said, just about any of the guidance units THAT WILL DO MAPPING will do what you want.  Some of the inexpensive ones without mapping may not be able to.  As Ted said, I would not look at a unit that does not map.  You will find all kinds of advantages to the map.  You can pick out places you missed.  You can skip passes and come back to them.  You can skip a pass and do that back corner and then come out on the skipped pass.  It is so much easier when you have a map to reference.  In the field that you showed, I would make the 2 headland passes and pop the A/B line while doing them.  Then I would jump right in on the NE corner and go to running the A/B line.  There is no need to go back to the west side of the field.

I have experience with 4 different units and all will do what you want here.  I have run a Mid-Tech Swath XL and a Zynx guidance unit.  I have used a Trimble Field Manager and a T170 on autopilots.  Any of these units can handle that pattern.

I do not know if you have many hills or not, but if you do, consider a unit with tilt compensation.  Especially if you are going to use it with the new air seeder.