I think it would be an easy sell to go back with the Auton. I mean, it lasted 16 years!!!
If you go with a cheaper company and there happens to be a problem that develops say 1-2 years down the road; how does that make you look? Is the customer going to call you back again or call someone else?

Also, please make sure you are selling the correct display technology. The 50" being a plasma display, had excellent off-axis viewing. The Sony is a VA LCD panel and does NOT have good off-axis viewing. Make sure all watching are seated in the cone of view for the Sony. If the seating is all over the room with people watching from off-axis on a regular basis, then you need to sell an OLED or IPS LCD display.