Mine is similar to Baz but the short version, although I got the Rhino tracks and these are also a good fit to the roof mounts.
Regarding width, I considered ther narrow width but decided to go with the standard slightly wider version. Other than the looks (which are subjective anyway) here's a couple of points I think are worth considering:
Awning - with more width you can mount the awning low. This gives less wind noise and keeps the awning close to the roof when its open. And reduces your overall height when the rack is not loaded but the awning remains fitted.
https://www.aulro.com/afvb/images/im...016/06/281.jpg
Shovel - The shovel would not be able to be mounted so snugly if the rack was narrower. Bit hard to see in this photo (red handle, head to the rear). It would still work but with the extra overhang it fits in there nicely.
https://www.aulro.com/afvb/images/im...015/10/780.jpg
Cheers,
Scott