1) use epc data to find part numbers http://nissan.epc-data.com/ (if unsure, get someone with Nissan fast to confirm the parts and also what other models share the part).
2) if buying genuine Nissan, get a price from Amayama http://www.amayama.com/?gclid=CLuStNCVhsMCFVVvvAodEQkAu
3) if not confident fitting parts yourself, go to a reputable mechanic familiar with modern japanese cars.