Mods for a 1986 Mustang GT 5- speed?

So far Ive added: A short throw T-5 shifter, deleted my whole A/C system (as it was unrepairable anyways) Kenny Brown hi-flo catalytic converter H-pipe, Flowmaster 2-chamber 2 1/2" exhaust, tweaked the timing, added 3.73 gearing, replaced plugs, wires, distributor cap, etc. Please list any ideas to help me along, I want my Mustang to be FAST, but keeping in mind It still has to p emmisions. It also has speed density versus the MAP sensor, I'm sure I'll have to upgrade this, I was also thinking about a larger than stock throttle body (65 mm) and a small dose of Nitrous Oxide (75-125 HP). Also the car has the stock (10 hole rims). Can I fit slicks onto these rims? Do i have to drill in to the rim with bolts to mount slicks on those rims? I live in Cook County, Illinois, so, after 25 years will I still have to p emissions? Thanks for your input! Mike~!