Based on what I've found, the 2nd Gen Red Line improvements were nowhere near as extensive as what the 1st gen got. It sounds like it basically got stiffer/lower springs (it is an inch lower) on the same struts as the XR - I don't think the swaybars are any different (RockAuto doesn't list any replacement swaybars for the 2nd Gen Vue, so I can't confirm, but Vue forum posts seemed to imply that they were the same). Whiteline does make stiffer swaybar end links, which could help (Moog's Problem Solver end links are also offered, and are definitely thicker/stiffer than stock - they were a popular upgrade on Cobalts - I run them with my SS/SC front bar).
However, also based on RockAuto, there are FE3 struts available, but I am assuming that both the XR and Red Line use those. So if you replaced your struts, shocks and springs, you could, in theory, go with the FE3 struts/shocks and Red Line springs. At that point, I'd pick up the Bilstein B6s for the front and the FE3 shocks in the back (Bilstein does not appear to offer B6 shocks for the rear).
Now, it might still be a longshot simply due to the nature of the vehicle, but since it is an Opel, there might be a few more parts across the pond that are available for the vehicle, but I can't really find anything.
