There's also Absolute Nature though I haven't tried. I vaguely remember running into some other texture mod but can't remember if one can install/merge more than one mod at a time.
The visual updates in Complete aren't going to blow you away but they do help. There is a Stalker Complete mod for each of the games. The first thing that comes to mind is Stalker Complete, it has a bunch of visual improvements but also some gameplay changes, though remains faithful keeping the original feel etc.
