Yeah, I think the Kawasaki were cheaper when I asked first a year or so ago. Quite expensive now and you are right, the IMD are about half price - can't beat that!
Unfortunately I haven't taken any photos of the IMD rings, and the mental image of them right now is a bit fuzzy. I remember asking around about them and got a very good feedback. I also asked IMD and they told me they are identical to the Kawasaki stock. I remember for sure that the top ring was shiny like chrome, second dark like cast iron. So, no question there. I somewhat remember double checking them up close to make sure that bevel goes the same way on all of them, but maybe that's just my imagination after all this talk about rings.
Anyway, they work great so far on my bike after rebuilding. I'm not an expert and don't have extensive experience on these bikes, but I think IMD would be the best safe bet for the money.
Just to be a devil's advocate, would I buy those Kawasaki rings if price wasn't an issue? Probably. Thinking in term of years, let's say 10, that extra cash divided by number of months of riding would not add to much. From that perspective, it would make sense to just get the oem set and forget the issue. It crosses my mind that perhaps those new cheaper rings might actually be better - technology advanced so perhaps the properties of currently made rings improved? That can't go beyond pure speculation though, unless putting both under microscope and lab testing. On the other hand, there are people with 30+ year old bikes with original rings and they ride just fine.
Final thought, I'd maybe ask again IMD specifically about the bevel and whatever else and then decide what to do. From what you said you will be putting a set of inverted forks, etc. etc. - not the cheapest things out there. Perhaps you'd go for the stock? In my case, with my budget, I was really happy to get those cruizingimage rings but unfortunately I know I'd be always feeling like I did a halfassed job, knowing there is a better set. So, in my case, I will be aiming at the IMG rings. My feeling is that they are a good replacement for the Kawasaki rings.