Well, the original safety devices cages were excellent, however I have heard mixed reports of the quality of the "safety devices international" ones, specifically that they seem somewhat difficult to get hold of and not all that good when you do :)
That having been said there are still some stocks of the older competition cages if you ask the correct people.
You need to work out what you are looking for in a cage though, full length? internal? external? and so on.
Internal cages tend to look better, but on a 90 you'll end up losing what little foot space you have and will likely get really annoyed with it. Are you going for a full roof? if so then you can get a fully external cage, but this won't pass muster with the ARC.
It's a complicated subject :)