I have been going through the older GTA games on PC in surround and the ThirteenAG fix works with surround.
http://thirteenag.github.io/widescreen_fixes_packWith the current version of the fix, you will notice that in surround mode the camera jerks around a lot when you drive close to something like a building, tree, or under a stoplight. I worked with him and we came up with a script you can install with the latest version of CLEO (2.0.0.0 is also compatible with the Steam version, btw). This script will be integrated into the next release of the fix, but until then you can find it here:
https://www.dropbox.com/s/ei62yvz1ywgmu ... jerkfix.csUnfortunately, in surround the crosshair is in the wrong place. I notified him of that too, but he said that might take a while to fix.