For that budget I'd definitely be looking for a HR mate.
It's the latest version of the 350z that was produced, easily noticeable by the twin intakes under the hood. Produces more power, nicer upgraded interior, bi-xenon headlights, LED rear lights, and you get the bonnet bulge
as chirag said and the HR has a higher rev limit too, only downside is it costs more to mod due to the dual intakes. if you we're planning on some heavy modding then maybe a very low mileage DE? all depends what you want out of the car i guess. personally i love my high mileage HR, but i bet you'd be hard pushed to find anybody that didn't love their 350, HR or DE
p.s. bonnet bulge and not for show either...