Vaio Power Supply

I need a Replacement Power Supply For Sony Vaio Desktop. The model is DPS-400LB A. I’ve tried to get a standard power supply from Best Buy and CompUSA and they won’t fit because the width needs to be 5 1/2" or less. This particular Vaio PS has two mounting posts on the side. The alternative to the Vaio PS is to get something that is 5 1/2" or less and I will find a way to mount it . Does anyone know if this exists?

It’s been awhile, so as far as I know Sony maybe still using proprietary power supplies. This means that normal power supplies will not fit in the Sony case and the best case scenario is to but a cheap ATX case and move everything into it and then get your power supply.