Sharpest zoom lens less than $1k ?

Lawnmower Shooter wrote:

Thanks for the suggestions guys. I am looking for a good sharp portrait lens for personal use, and have also been asked to shoot a friend's wedding reception so the extra reach would be useful for that. The 50-135 or 50-150 sound nice, I will have to compare prices and see how it looks. I was wondering if anybody can advise, how are these two in comparison to the pentax 55-300, at even focal lengths of course? The 300 wouldn't be as necessary for my purposes, but I would like to get into birding eventually too. If the 2 mentioned are much sharper than the 55-300 then nevermind, I am after absolute sharpness for now.