I think the general consensus (correct me if I'm wrong) is to have the tint dark enough so that it hides the crap around the monitor/tv. In my case, the place I got my tinted glass from only had one level of tint-darkness, but I could choose from 'bronze' or 'grey'. I went grey and it looks awesome. I guess the darker the tint you get, the more you crank up the monitor brightness/contrast to compensate.
My cab was built from scratch and I simply attached 2 timber rails on the cab's sides to rest the tinted glass on, plus a ridge at the bottom of the monitor to support it (monitor sits at 45 degree angle). The glass is not fixed to the cab in any way, but its pretty heavy (6mm thick toughened safety glass) so gravity keeps it in place.
HTH!