It aint gonna happen as it seems like Wren, the FO, and Fredi all have a huge mancrush on Laird, but the guy brings nothing to the table. Terrible all around catcher, terrible pitch framer, not that great defensively, and brings nothing offensively with the exception of a occassional blooper. He's horrible IMO.
Patton is a guy with some upside, and probably would be Eric O'Flarety 2.0 in the pen, with Venters coming back along with Avilan it would give us a great trio of lefties late in the game to bridge the game to Kimbrel.
As far as the backup C spot if we traded Laird, it wouldn't be that hard to find a replacement. I'd look at Betancourt to see what he can bring, if nothing else he is leaps and bounds better defensively that Laird. His offense is a question, and I question whether or not he will ever get there, but a little call-up can't hurt anything at this point in time. Hell, I'd look at a Henry Blanco type that would be easy to get as a backup, in fact, with his defense, he would already be an upgrade over Laird.
At this point in time, Patton is measureably better than Laird or anyone else that could be acquired.