93 Chrysler Imperial with a different but broken Master Cylinder

I have a 93 Chrylser Imperial I bought from my fience's father. It's in rough shape, but it's my first car and I'm automacanicly declined. It's been working fine so far, untill the brakes started acking up. It needs a new master cylinder. The big problem is, it doesn't have the standered Master Cylinder, it did come with the car when it was sold to it's first owner. So it must be an optional part. I don't know it's name or company, all I know is the paper said 1200 - Master Cylinder w/ ABS. I have a picture provided showing it. The mechanics said they have some, but it's costs alot of money. Basicly, I need three pieces of information: What it is, how to remove/install, and, if possible, if you know where I can get one cheeper. Doesn't matter where it originates from, as long as I get it. I have someone who can work on it, but he only knows fords, not chrylsers. Can anyone help me?

http://i534.photobucket.com/albums/ee342/erpm08/MasterCylinder.jpg