Well if you're going to pick one lens, sounds like the 43's a pretty good pick!
The FA77 should also be on your list. Faster, sharper in the middle than both, and beautiful rendering, in my opinion. If you love the 43, you'll probably love the 77.
The DA70 focuses very fast, gives a very even (and very good) resolution and is noticeably lighter and less than half an inch shorter than the 77 if that's important to you. I personally prefer the look of the 77 wide open to the 70.
Originally Posted by FHPhotographer 
I'm letting the side down by only working with one lens (43 Ltd) on the K100D, but I would like to add a longer prime. Most of my stuff ends up converted to B&W, natural light, so resolution and contrast are high on my list of virtues. I'm at an impass between the DA 70mm or the D-FA 100mm, the former for size and speed, the latter for reach and very occasional macro.
Comments on what works for candid street work and portraits, close-in detail of found objects? Thanks for any input,
Brian (FHPhotographer)