Hi, I'm WhiteDragon25! While I don't have the technical expertise to actually create a mod, I do have a wealth of ideas and concepts for one. You can see my mod ideas here on my profile blog, where I talk about them in detail.
The Centurion was a remodel/redesign of the Slingshot done for Tiberium Wars Advanced, and was in Version 1.4 (or was it 1.5? 1.52 is the current version... bah, I don't remember, point is, it was in a previous version).
The thing about the Centurion that I like is the turret redesign, far sleeker and realistic-looking than the Slingshot's design was; the one gripe I have about it is using a twin-gun system rather than the quad-gun system that the Slingshot has. Other than that, though, the Centurion's design is certainly one I would use in my Tiberium Incursions mod project (just slap on two more guns).
Incidentally, this is the first GDI piece included in my image gallery.