Plenty of good advice here. I don't think anyone can tell you what focal length will suit you best; some will prefer a 21, others a 70.
For me, the main thing I dislike with the FA28 and FA43 (and the DA35/2.4) is the lack of Quick Shift. That, and a distance scale, would for me be reasons to go for a DA Limited for street photography. I think the 40 or the 21 would both be excellent as a first prime.
That said, my first auto focus prime was the 35/2.4, and I find that to be an excellent lens. It wouldn't be my first pick for street shooting, though.
Whatever you choose for a first prime you'll soon have to figure out what the next one will be