Good choice even though the majority of 370Z owners would rather mod their cars as per their desires. With Nismo, you're forced with their exhaust, their ECU tune, their kit, spoiler & suspension. I'd rather get an FI exhaust for instance, some KW coils and wait for a body kit sexier than that of Nismo's, saves the $$$. You'll need to retune with Nismo anyways if you install Intakes, HFC, headers etc.. so there goes the money spent on the Nismo tune.
In brief, if you're keeping her stock, get Nismo otherwise get a Base 370Z and mod her like a true gearhead
My 2 cents