With LF, you can easily push HP5 or other 400 ISO films without the typical 35mm shooter's concern for grain. I've yet to notice any at all shooting a crown graphic at 800, simply developed in D76 1+1.
You'll need 125/s at least to stop people motion in the street. With a 135mm press lens (or similar), you'll get reasonable DoF, and these older designs often shoot sharply at wider apertures. A press camera with a working rangefinder will help if you want to go hand-held (I use the wire frame and the RF).
Consider also using a flash like a Metz CL4.
I've been doing some handheld 4x5 like this for about a year and am about to start using a very lightweight tripod for LF street work, fwiw.