Requesting a stealth script.

Okay, so I'm so close to having the scripts section done for my game. My database is 99% complete (leaving it as "incomplete" so that I can add some smaller items like collectibles later on if I want), and I'm almost ready to begin the actual game. However, I've run into difficulty getting one aspect of the game ready.

I've tried out a couple stealth systems. And all of them are glitchy and buggy, and don't work the way I need them to. So, here's a request.

Is there anyone who would create a simple stealth system that let a guard or someone see a few spaces in front of him (even when he's walking) and have it so that when the player steps into that line of sight, it turns on Self Switch A for that guard. And if you walk up to him and press Enter on him from behind while his back is turned, turn on Self Switch B. Is that making sense? Anybody willing to do?

EDIT: Also a switch to turn the script off, and some way to not allow the vision to go through other "same as character" events.