Look at maximum motorsports handling packages, Griggs racing is good too but expensive.
Full legth subframe brace welded in, tubular K member, torque arm/panhard (or watts link) setup in rear. Coilover conversion all around. Caster Camber plates. Welded roll cage. strut and shock tower brace. Weight reduction. Good Tires are going to change the feel a LOT. Lighter wheels, lighter flywheel, lighter driveshaft, a good LSD. If you could afford this, your car would be a beast. Bigger sway bars.
Even with you engine completely stock, the above car would be amazing to drive