Originally posted by Hugo Bucussi but I would like to take nice pictures of him jumping and running around, so I need a camera that can take pictures fast(as far as I know).
For successful pictures of dogs in action there are a number elements in play:
1. Fast shutter speed if you want to freeze the action completely (not always desirable, but that is for another topic)
2. Continuous shooting mode where camera takes shot after shot as long as you keep shutter button depressed.
3. Continuous Autofocus where the camera will track your subject as he moves closer/further from you.
4. Suitable lens.
1+2 will not be an issue as the K-5 in all it's versions is very capable.
3 and 4 may be more problematic depending how quick your dogs move ! Hopefully someone with experience of the K5 versions can give more detailed advice, but the "kit" lens may not be your best bet for this as it may not be able to keep up as well as more modern lenses. If money was no object I would advise the K3 III and the D FA 70-200 f2.8, but that kit is way out of your budget. Possibly the K 5 II + DA 55-300 (
check compatability) would be better suited specifically for action shots.
For all your other intended uses...still shots/portraits the K5 + kit would work perfectly.
I hope this helps even though I realise I have given you more questions than answers.