What is a *good* 50mm lens for a pentax K1000?

[ebline]

I would like to invest in a decent, versitle, manual focus 50mm lens to fit a pentax k1000 body. I'm not sure what other brands will fit this camera. I would like to be able to enlarge my prints to 11x14, possibly 16x20. I shoot mostly black and white fine art photography, so sharpness and detail matter at these sizes. Thanks!

[another view]

I've heard that the 50 f1.7 is one of the best 50's ever made. I haven't used it, had a K1000 years ago but only had the f2. Michael Johnston has written about it somewhere: www.37thframe.com