Its not completely necesary, but you will notice a difference. A set of MM lca's would compliment that nicely. You can get the uppers if you really want, but they tend to bind unless you're using a spherical bushing, and I would make sure your torque boxes are reinforced. My next step is to get a panhard bar, and use one of the stock uca's as a poor mans three link.
---------- Post added at 08:46 PM ---------- Previous post was at 08:45 PM ----------
As for the front, unless you're going to a tubular setup there's really no need to do anything there.
2000 Mustang GT-Former giggle gas addict
1990 Mustang GT w/ Vortech V3
***resident gun idiot***