Pentax K=mount lens'

Looking for some K-mount lenses for a new DSLR I got. Old Pentax, Sears, Tak (not M42 screw mount) Ricoh, etc. Especially non zooms. Auto focus or not, really looking for a Pentax SMC 50/1.7 or similar "prime" lens, usually found on old 35mm "B team" SLR cameras (not Canon, Nikon or Olympus). Im getting out of my cool-aid Oly and Nikon phase. Pentax was sort of the "AMC" of the Camera industry. They made some great stuff (70 Dogleg heads) , but the marketing wasnt that strong. I'd say Olympus was the "Chrysler", usually 3rd in sales but had a fierce loyalty. Nikon was GM and Canon was Ford....