Already with the K20, you will see improvement on this, compared to the K10. K7 should be even better.
But high-end Nikon and Canon, does more fps, and have a long reputation for AF-c
Maybe rent or borrow a K20/K7, and figure out what you wanna do. (There are a lot of Australian Pentaxians. And maybe some stores have rental programs)
Here is a thread, with more info on the subject :
https://www.pentaxforums.com/forums/pentax-news-rumors/25521-magazine-review-...good-info.html
K20 get 75% of images in focus with AF-C.
AF-C is rally the Achilles heel of the K10. I'm impressed you've managed for so long