ok well here are some nissan sites
www.heavythrottle.com( sr20det swap info and jdm parts)
www.xatracing.com(jdm engines, parts, nissan, toyota, lexus, mazda,)
www.phase2motortrend.com(nissan sr20det engines and parts)
www.motorex.net(skylines galore, parts, you can buy us legal skyline from these guys.)
www.importintelligence.com(mostly deal with custom gauges but they can get you whatever you want) also they are local.
i know alot more i have to get my lists.