You asked
Best camera for the pentax hd da 55 300mm f 4 5 6 3 ed plm wr re?
For this lens, I'd start with the Pentax K-3 Mark III. It's the newest APS-C body on the list, and this is an APS-C lens, so you get its full 82-450mm-equivalent reach without any cropping.
If you want something different, the Pentax KP and the Pentax K-3 II are also solid APS-C pairings with this lens.
The Pentax K-1 Mark II is a full-frame body, so the lens only works in APS-C crop mode there, at fewer megapixels. Pick it only if you already own that body and want to use this lens on it.
One thing to know before you buy: this lens isn't stabilised, and it gets darker as you zoom in. Bright light or a steady support helps a lot at the long end. The full lens page has the complete camera list.
Written by Claude from this site's pages.