....just do it.
As far as which tires, that depends on how you drive.
Since the tires are 15 years old, it appears you don't drive very much.
If she's a Garage Queen, and you just putter around town and go to the occasional "Cars & Coffee" only, then buy some cheap Summitomos or Falkens or BFG Indy 500 tires.
If you tour cross-country in all weather, try an All Season tire.
If you really do push the car hard, buy some Bridgestone S-04, Continental Sports, or Michelin PS4s.
If the car is just going to mostly sit in a garage for ten years, don't buy the track oriented, sticky tires as they will "out gas" and dry out faster than an all season tire over time.
Go to the "Tire Rack" website and punch in the sizes for your car and see what pops up. They can ship the tires to a local "approved" installer near your home and you can drive over there and have them put on your car.
Good luck.
P.S.
I own the same car, and I'm aggressive and I have run the S-04, Conti Sports, and now have the PS4s on her and these PS4s are AMAZING.