Hi Steve,
From what I've seen the SNG one and the one from CMC are the same, so that narrows it down to two.
There was a recent topic on here about the Superspoke one.
My observations, and this is only my personal take on the two are as follows.
CMC / SNG. Closer to the original look of the existing boss and in my opinion more in keeping with the car.
Superspoke. Better engineered but for me not as nice when viewed from the side.
I have no affiliation with either and am like you still at the research stage.
Probably no help at all.

However there are a few threads on here if you look and a fee videos on YouTube.
Edit. I've just noticed Steve has replied while I was typing, his link is worth a look.
Simon