Voigtlander 125 seems to be a good deal (if you can find one).
Bset bet: take a good hard look at the Sigma 180/3.5. The images I've seen are quite good. Obviously I cannot tell for certain, since they are web-sized images.
OTOH, I know my FA* 200/4 is insanely sharp. The images, assuming you've done a good capture (ie. windy day, etc.), show no softness in the DOF at 100% image size in CS2. Sharpening would actually ruin the image!!! Ask Chris (codiac2600) - he's seen the images about any softness... none... zero...
BTW, it is much kinder on the pocket book at around $800, but sometimes
Digital cameras, canon digital cameras, sigma digital cameras, digital camera accessories, hoya filters will have them. Those copies may have cosmetic blemishes on the barrel, but no issues with the optics. They'll be around $550 - $600 (when available)...
Cheers,
Marc