You don't need to match SF2 on the globe with the SF2 on the display or anything like that. 

As mentioned, you can get free SF1 signal which is better than WAAS from any SF3000, 6000, or now 7000 receiver. SF1 from those globes on the roof will work with any 2630 with any AutoTrac activation. It's a bit confusing because people selling 2630 displays will often call that something like a "2630 with SF1" or "with SF2" which actually means AutoTrac SF1 or AutoTrac SF2 which is lifetime activation to auto steer on the display. The 3000/6000 globe can have SF2/SF3 permanent activation on it which is pretty costly up front originally and then user would pay for a 3 month or longer subscription for more accurate signal. RTK is of course another activation above that and then you have options for RTK accuracy. 

If you want to use any higher accuracy GPS signal and/or SF1 you need AutoTrac SF2 (AutoTrac now) on the 2630. "AutoTrac SF1" can only steer on the free SF1 signal but they did away with the 2 different versions years ago as far as what was for sale. It's a $250 upgrade to take the AT SF1 to the full version so not a big deal to take the lower level of AutoTrac and make it the full version. 

The SF7000 is the brand new receiver and for most new users like you will either have the same free SF1 like the rest or you would not need any of those pricey lifetime activations, just pay $1500 per year for SF-RTK and get satellite based RTK. 

Clear as mud? Ask away