Well I'm not too sure on the questions as such but definitely a 350z. I drove a Boxster and its uncomfortable, cheap for porcshe interior and generally the enjoyment you get from a Zed is amazing!
In my opinion, as long as it has a full service history at a respectable garage (ideally Nissan) and the body work is good its all good but take someone mechanically minded with you!
I'm sure some of these other guys will let you know what to look out for.
Good Luck!