I say the 24-70 (either or, personally. People loved the original lens, it's funny that people no longer consider it an option now that it has been replaced) or 24-105.
I would think the 24-70, though a bit shorter at its longest, will be more useful as you can use slightly higher shutter speeds.
IS won't help you with moving subjects, and the street is rarely still.
That, and the obvious flexibility with framing the subject quickly gives tremendous advantages.
By time you step closer or farther away, you may have lost the golden prize of a shot.
Then you evaluate the advantages of a fast prime.
While I <3 bokeh as much as the next photog, I feel that street photography benefits from putting the subject in context.
If everything is a 1.2f - 1.8f blur of creamy goodness, what's the point of shooting on the street?
What I really look for in great street photography are the details that support the subject of an image.
Maybe a ratty old building, a person off to the side doing something irregular, or a cat that you notice after looking at the image for 10 seconds or so.
It's all subjective however.
You may enjoy obliterating the background every now and again, so it comes down to your taste.
