Instead of spending $6000 on upgrading a 318, why not take $3000 or so and buy a 328 first. Then, if you want, you can mod that car.
Given a ZIP Code of 20897,
Kelly Blue Book Retail value (in USD) is as follows
1997 BMW 3 Series 318i Sedan 4D
Engine: 4-Cyl. 1.9 Liter
Transmission: 5 Speed Manual
Drivetrain: RWD
Mileage: 84,000
Excellent $6,925
Good $6,395
Fair $5,705
1997 BMW 3 Series 318is Coupe 2D
Engine: 4-Cyl. 1.9 Liter
Transmission: 5 Speed Manual
Drivetrain: RWD
Mileage: 84,000
Excellent $6,925
Good $6,395
Fair $5,705
1997 BMW 3 Series 328i Sedan 4D
Engine: 6-Cyl. 2.8 Liter
Transmission: Automatic
Drivetrain: RWD
Mileage: 84,000
Excellent $9,450
Good $8,775
Fair $7,925
1997 BMW 3 Series 328is Coupe 2D
Engine: 6-Cyl. 2.8 Liter
Transmission: 5 Speed Manual
Drivetrain: RWD
Mileage: 84,000
Excellent $9,400
Good $8,750
Fair $7,875
I'd buy a 328 and add wheels instead of adding all those mods on a 318.
You'll love the power, and it handles too.