I agree to go with an 8N over a 2N or 9N. My 47 2N has the brakes on separate sides, which is no fun. Also, has pegs instead of floorboards (believe the same to be true of 9N).
What I will say is that the N series have a regular 3 point hitch, which means you can use them with all the usual 3 point implements. I like my N, it's a pretty versatile machine when used within it's limits. They are dirt simple to work on, parts are very available. Just remember, it's a ~20 HP machine. So, just because it's a "full size" tractor, it doesn't have a ton of horsepower.
Couple of fairly big gotchas to the N series tractors:
No "live" PTO, which means when you have the clutch in, the PTO stops. Not a HUGE problem, but something to keep in mind.
The PTO is not separated from the rear axle. When using something like a rotary cutter, you MUST use an overruning clutch or when you try to stop, the cutter will keep trying to push the tractor, making it hard to stop.
No "live" hydraulics. When the clutch is in, you cannot raise the 3 point. This is a big pain in the butt. It means when you are stopped and want to raise an implement, you have to put it in neutral, let the clutch out and raise it. So, when you want to turn around after pulling something like a rake or blade, you have to get to the end, stop, put in neutral, raise 3 point, put back in gear and turn around.
PTO must be engaged to raise the 3 point. Not sure how common this is outside of Ns, but can be a bit of a problem if you forget.
No external hydraulics. You won't have remotes for running anything like a top link or any of the other cool things these guys do with their newer compact tractors.