My personal experience with a Kohler door was really bad...first, big mistake, I ordered it from HD. They strung me on about shipping (Kohler - I listened while they called multiple times) for months saying it would ship tomorrow. Then, they sent the wrong door. I was taking a long time to remodel, so it wasn't hugely inconvenient, but still annoying. I don't really like the way it works, and the unit I bought had the trim painted (white) and the paint is coming off in places (about 5-years). The holes for the roller bearings were all chipped and I worried that that may be a start point for a crack (not good on tempered glass!), but it's sayted instact so far. They also didn't seem to be properly placed as there's some drag and you can't adjust it to get it better. If I were to do it again, I would NOT buy it.
I put one in at my mothers from Century that seems to work quite well. There is only a small teflon like block in the middle that helps guide the thing. Rolls silently and easily. Decent quality for an off-the-shelf unit. I'd looked at them, found then nice, but my local supplier wanted way too much. She was able to get it much more reasonably where she lives (who knew?).
If you want to go custom, you can get the glass locally and the hardware from www.wilsonglass.com that stocks lots of things you don't see very often. Good people to work with.