Naws, Turbo, Exhaust, Headers, Intake, Exhaust, Igintion, a whole bunch of stuff, all depends on which direction you wanna go
whether it be naturally aspirated, daily driver, or turbo....
here are some sites
www.civicsuperstore.com
www.nrg-racing.com
www.diabloautoposrts.com
www.modacar.com
www.summitracing.com
www.jcwhitney.com