The one I got was the Kinesis Advantage 2, which I almost hesitate to recommend due to the sticker shock. I'd recommend trying to see if the idea of a more symmetrical typing posture appeals to you enough to be worth it (maybe just some non-typing exercises at your desk). I was at the point of having already adjusted my chair, desk height, and wrist angle (making sure not to rest the wrists while actually typing), and the keyboard was something of a last resort. That said, I am very satisfied and wish it were priced more competitively so it could be a more ubiquitous option. I ended up getting a hard shell briefcase to carry it around in while I learned to type on it (which took around 2-4 weeks, after which point switching back and forth with normal keyboards became less of a hassle).

I was on the fence there for a while between the two designs, and now that you mention it I think the shoulder-width separation is at least as important for comfort as any other factor. I ended up going for the Advantage2 instead mainly because of the mechanical keys, since the two bottom-end Lenovo keyboards I was using previously got to where I had to forcibly "pop" some of the keys down to type and I wanted to minimize my chances of a similar experience. Though, I doubt the problem happens quite like that on any but the cheapest of keyboards.

I really do wish they made a separable Advantage version. The ErgoDox seems as evidence that there is at least some market for such a thing.