I just looked at the top one. IMO, 23 is too small for a grey. BY the time you put perches, toys, etc. it will be quite small. I wouldn't buy anything under 32". All mine are macaw size cages, as I work and they have to spend 8 hours in them on most days. I have had my cages for going on 8 years, no chipping or cracking.
If price is an issue, I would purchase the largest you can afford and not worry about the stainelss steel. I havent heard of a grey grasping the bars enough to the point that the powder coating chips off. In fact, my greys and amazon never grasp the bars, there is too much else for them to do.