I also see that you are new here, so ill also fill you in on a secret.....
Some subjects (questions) can be answered by doing a search. Alot of guys here dont like to type out several paragraphs over and over again, only to be asked again. No flames intended, just thought ide let you know....
Now on the fan question.... In short, yes, the Mark VIII fan is a very nice upgrade for the fox mustang. There are a few guys here that are running it, (I will be shortly), and its very simple to hook up. The hardest part is finding a good way to secure it to the radiator. Oh yeah.. and of course, clearance.
To control it, there is a new relay type unit made by www.dccontrol.com
they make a relay that was designed with the Mark VIII fan in mind. No need for a switch, the DC controller takes care of everything.
One more thing... you will need a 130amp alternator. The stock 75 amp alternator will soon become toast if you try to run the fan along with other accessories.
and remember... the search button is your friend.