I would measure the entire distance from one side of the bike to the other where you intend to put the lock then compare that to the amount of space left on the inside of the lock. You would then know what sized things you would be able to attach to. If you envision locking to bigger things then the larger lock would be better.

Do you have a bike rack by chance that you could strap the NY to? I have also see folks hang the lock from the seat stays and through the front triangle to store the lock when not in use. If I remember right the guy said he had no problems with it. The straight part of the lock went across the top of the stays and the U portion was wrapped around the seat tube.