Upgraded and in love!!! Hello from AZ!

SOUTHZZ

Great upgrade.
On the rear spoiler. There are so many designs available.
Its pretty subjective due to the look you want. larger/wing
or,a spoiler that blends. I too had a 350Z. My spoiler choice was
a Blitz. It really blended with the lines of the car. IMO,you go with
a large wing,you almost need other parts on the car to balance the look.

Away from your spoiler question,on your white Z ,I'd do some carbon fiber accents.
Consider B-pillar covers. I did my Z with these with matching side mirror base accents.
Got mine on Ebay from ZCF.
Good luck.