You might know this, but to anyone else who doesn't that is reading this and is new to digital SLRs, the K-5 and K-3 variants have an APS-C sized sensor, smaller than the older film 35mm SLR bodies you probably are used to using.
This means to get an equivalent field of view, you will need to calculate the crop factor for your focal lengths
So, for instance, 50mm on Full Frame (35mm) is equivalent to 75mm on APS-C (50 x 1.5 = 75).
I don't know your budget.. skys the limit with a lot of this.. but I'd look at these if starting out (with a bit of money available):
DA 16-85mm WR for landscape or a Sigma 17-50 f/2.8 for landscape and street (the WR is weather resistant, the Sigma is not so dont take it out in humid/rainy enviros)
DA 105mm WR Macro
DA* 50-135mm (essentially the APS-C equiv of the 70-200mm. kind of big though so not really a street lens)
DA 35mm f/2.4 (a plastic, yet sharp lens that equivs to roughly that of a 50mm on FF -- cheap starter street lens)
DA 50mm f/1.8 might also work
HD 55-300mm WR (cheap, but fairly sharp telephoto. noisy since it uses the screw drive and it isn't a sports lens but it is really nice for the price and size)
I think the best idea is the old idea of taking your K-3 and 18-55mm kit lens out and shoot at various focal lengths. See if you favor a specific focal length in your zoom's range or if you feel like you need more reach. Go from there. And please make use of the lens reviews on the site:
https://www.pentaxforums.com/lensreviews/