i would go the S13t personally. if u dont like the slightly dated look of the silvia lean towards a 180sx. they have clean lines and a great power to weight ratio. they are also extremely well balanced IMHO. plus once you start modding they pull hard and are heaps of fun.
But thats just my opinion. at the end of the day the decision comes down to what you want and how much you are willing to pay. it generally boils down (like everything else) to you get what you pay for. You shouldn't really need to come on forums asking everyones opinion about what you should get because if everyone had told you to get the NA R33 then you would find that at the end of the day, when you're longing 'Gate, you will be disapointed and wish that you had made your own decision and got the turbo.
Good luck hunting man.