As a very new owner of 350z I can only give you one advise : buy , modify , enjoy
It took me a year since i first thought of buying one and now I know a I lost a year of great fun, so don't copy my mistake.
Good luck in your hunt
Finally... finally I put my hands on 350z. Joined this wonderful forum a year ago and learned a lot , many advises and useful info which helped me to buy my dreamed car. Thank a lot and see you on a roads Ladies and Gents.