Lens for K20D. F 70 210 f4-5.6.

Unless you have a specific reason for wanting an older lens, the best general-purpose tele zoom for a pentax is the 55-300 which is very good for the money.

What is it that you don't like about the Sigma 30mm?  It has a good reputation.  if you want the flexibility of a zoom than as has been said you could get an 18-55 cheaply - but I would still keep the 30mm f/1.4 for low-light use.  A combination of 18-55 + 55-300 + the 30mm f/1.4 prime seems to me like a pretty good kit.

Best wishes

--
Mike
http://www.pentaxphotogallery.com/artists/mikeward