Depending on the age of the rate controller, a 2600 display is probably fine. Actually, I don't think the 2600 has ISO capabilities. The 2630 is probably your better choice. Just make sure it has a Section Control unlock. You will probably also want to throw an SF3000 on your cab as well for best speed and accuracy signal. You can pull a GPS signal from the FM-750, but why do that when older Deere receivers are so cheap right now, and SF1 is a good free, better than WAAS signal?

Also, I had a planting tractor with 4 monitors for a couple years and kinda liked it actually. Until it got dark and the whole cab glowed.