[84LX89GT]

I've had quite a few fox bodies myself:
1991 Mustang LX 2.3
1989 Mustang GT 5spd
1984 Mustang LX 5.0
1983 Mercury Zephyr 4dr 3.3L (fox body)
1981 Ford Fairmont 4dr 3.3L (fox body)
1983 Ford Fairmont Futura 3.3L (fox body)

I love these cars and just can't get enough, i'm building an engine and trans for one to be decided. I'd like to get a early 80's mercury Capri, but they're harder to find.

With an '82 GT at the very least i'd pick up some shorty headers (maybe even '85+ stock headers -better than '82's manifolds), a 4 barrel intake manifold and carb and a different camshaft plus some better rearend gears (or swap 8.8" rear axle with better gears) and you'll have a fun, quick and inexpensive car.
The awesome thing about mustangs is you can do anything under the sun with them and the amount of combinations you can put together is almost infinate.