Suspension: re-do all the bushings. Parts are cheap but it's labor intensive work, so do it yourself and save. Research the archives here on the how-to.
Then add the strut tower to firewall braces from a boneyard GT or new from IPD.

Performance: skip the cone filters; they breathe hot underhood air. Pull the filter box and remove the thermostat, and wire the flapper door so that it only takes in air from the grille (i.e., block off the heated air inlet). Remove the little trumpet-like thing from the intake duct behind the headlamp - it's just a silencer and it restricts airflow at higher revs. Can't get much cheaper than that. Make sure plugs, wires, cap & rotor are all up to snuff. Beyond that you're into cams and turbos.