Alex,
All of those are manual focus. Both of the Pentax lenses are are also manual aperture, not sure about the Hanimex but it is likely all manual as well. Auto-focus lenses will be an order of magnitude more expensive, mostly in the $200 plus category though you can always hope for a deal.
Read up on using manual lenses on new Pentax cameras
here before you jump in, so you understand what you are getting into.
You do not say what camera you have but I assume APS-C if it is digital.
Quote: Secondly am I best to go for a bigger aperture but larger focal length (50mm 1.7 first link) or smaller focal length and smaller aperture (28mm 2.8).
That really depends on what you want to do. On film the 28mm was the wide angle and the 50mm was the normal or standard lens. Really designed for two different purposes. 28mm is not really wide angle on digital and the 50mm is more of a short tele.
The large apertures (small numbers) are useful for two things:
1) isolating your subject with a very narrow depth of field
2) Taking shots in very low light
With the use of higher ISO on digital the use of really large apertures is starting to be debated as far as low light is concerned. Isolation and depth of field still requires a large aperture though.