Great advice from CBBaron.
Stay the hell away from a 600cc sportbike…at least until you can make a beginner bike your B#$% Good reasoning there, though I feel you on the good looks thing. It’s hard to turn away from that, to be sure.
So of all the other bikes that you listed, I have ownership experience with two and riding experience with another two. I started on a 250R myself way back when (still own that), then got a 600, and most recently picked up a DR-Z400sm. I think both the 250R and the DR-Z are fantastic beginner bikes. With your height and weight, and especially if you’re into dual-sports, the DR-Z might be the way to go. It has more pep (though the same top speed thanks to low gearing) and will be less cramped than the 250R. I’m 6’4″, so I needed to get lowered footpegs to even be able to ride the 250. You may have the same problem. Note that the size issue won’t exist if you get a pre-’08 250R, since they didn’t have the same gas tank shape.
I’ve also ridden the GS500 and the Ninja 500R and believe them to be solid beginner bikes as well. The only thing that differentiates them from the other two bikes is a bit more power, and I think both are in need of serious updates to their appearance. That damn 500R looks like it’s from 1987…oh wait, it is!
The money issue is legit, though if you want a new generation (’08+) 250R, you’re probably going to pay about the same as for a used DR-Z400sm. Honestly, go sit on all the bikes, think about the kind of riding you’re going to do, and based on what’s comfortable and fits your needs, make your decision.