I think I might've been a bit rude, so I apologise.
The fairing you are asking for you could probably find at any sporting goods store that carries Thule roof rack systems. I know, I seen those almost everywhere in Chicagoland area. If I am not mistaken the number you are looking for is 870 - it has to be 38" long. You can order it from any web site that sells Thule, but shipping will run you extra. Check the stores first.
Don't aks them about VX roof rack and what fits that, because none of the dealers - at least the ones I dealt with - even know where to begin looking for ansfers.
For this particular fairing you are going to need horizontal mighty mounts. The mounts that come with Thule fairing are sqaure, and will not fit our bars. Go to www.isuzuparts.net or even better call them at 1-800-543-8067 and ask for them. The part number I have from their invoice is 2-90116-905-0 and they call them Wing Bar Mighty. They run around $16.
Btw, don't get scared, the real name selling for isuzuparts.net is Bruce Titus Automotive Group. They really know a lot about Isuzu, and are very helpfull with parts for VX.
Hope that helps.
yal
EDIT:
Yakima carries similar mighty mounts, but they don't have the right size for VX's cross bars. Thought I'll spare you time for looking and fitting.