I apologize that I haven't posted an update to this issue. I was able to get the ATI proprietary drivers to work! I haven't been able to re-test and I am going from memory here but basically what I did was follow the advice on ATI's website.
I downloaded the ATI drivers and got the binary file ready to run
Removed all of the generic and ATI drivers that I had been trying to install via Synaptic
Rebooted > Because there is no active driver X11 hates you
From command prompt I executed the ATI proprietary driver installation (It will look like an old Slackware distro gui installation; blue screens, etc)
Everything has worked perfectly afterwards.
The Catalyst drivers are install and the Catalyst control center application works. If I have the time, I have been planning on doing a full disk encryption and doing a full disk installation of Linux MInt and if I get around to it then I'll make sure I document my installation of the drivers and update this post.
To get the fn+brightness controller to work on the laptop I followed these instructions and it works perfectly: viewtopic.php?f=59&t=112095