The length as well as other useful information can be displayed by rightclicking the column headers. Also, please leftclick the bitrate column header and you will be able to sort all the files with "embedded" bitrate to the top.

Additionally, if you select the "Audio" choice while doing a search, and check "More Search Options", you can even enter search criteria depending on these factors you have mentioned.

I will also mention this to the developers. We've had a few requests more advanced search criteria.

Hope that helps!
Avi