Well your not a big autocrosser/track guy so suspension is almost pointless. You seem to want a good looking fast car even though your car is auto so I would recommend..
AA gen 3 exhaust (not to agressive but a nice sound) 600$
AA CAI (a nice mod) 350$
AA Software 350$
The rest I would spend on headlights or some nice used bbs rims.
Current standings: 98 M3 Track car
Mods: suspension, i/e/fly only
1/4th mile: 13.7@101 on 235/40 streets
Rd Atlanta: 1:44's on RA1's, 1:46 st.trs
95 M3 3.2obd1