There is a pretty easy and cheap fix for the shifter too! There are three bushings that are probably worn out or completely gone. On the pin that holds the shift lever into the transmission, there should be shouldered bushings that go between the shift lever and where the lever attaches to the trans. I don't know what that piece is called...sorry. Those shouldered bushings actually go into the shift lever and the pin that holds it into the trans goes through them. Now, that will help the side to side slop...the front to back slop is controlled by the small cup bushing that goes at the very end of the shift lever that engages the transmission. That bushing is likely the first one to go. If you get the three bushings and put them in, you'll think you just bought a new transmission. The nice thing is this...those will be the same bushings that you'll want to use for the 5-speed when you decide to make the change. Money well spent.
I just found these bushings on eBay and they're pretty cheap! I've linked them here for you...
Shift Lever Bushings: Shift Lever Bushings
Shift Rod End Bushing: Shift Rod End Bushing