Both of those tonearms are great ones, and with the compliance rating of 15cu on the ZYX, I don't think you really have to worry about matching with either of them. Pick the one you like best.
If you want to split hairs, the OL Illustrious will likely provide better bass response, and the Graham may be a touch more liquid in the mids. I think the OL Illustrious will be significantly less money than the Graham, so that may tilt things in its direction.
I prefer the Illustrious because of its gimbal-bearing design, but it is very hard to find fault with a Graham 2.2. Either one will be an awesome sounding combination with that ZYX Airy.
If you want to split hairs, the OL Illustrious will likely provide better bass response, and the Graham may be a touch more liquid in the mids. I think the OL Illustrious will be significantly less money than the Graham, so that may tilt things in its direction.
I prefer the Illustrious because of its gimbal-bearing design, but it is very hard to find fault with a Graham 2.2. Either one will be an awesome sounding combination with that ZYX Airy.