I've been a customer of Jack's since around 2004, and never had a bad issue. If there were ever any issues, they always take care of me and sorted everything out. Jack's does have units there(not always for GVR4, but its worth a shot), but be aware: If you're going to go there for a basic rebuild and all that jazz, a core is necessary or you'll be spending $200 extra for thier core charge.
ALSO: the easiest way to get ahold of someone at the shop is via email. There are links on thier site with their contact information.
Hope that helps!
-Jake
P.S. The part number they list in that ad is a FWD trans, part number, not an AWD trans.