Woothemes has a theme called Listings that would do almost everything you are looking for. Listing theme has frontend posting capabilities built in but and is made to be a classified style theme but it is not free.
This is another good one. http://www.premiumpress.com/classifiedstheme/
App themes also has a theme called classipress that is much like the listing theme.
The Elegant Themes has a few themes that could be used too. eList is one, the ask it theme could be used with ease. I think InReview may work too (not sure) – All of these themes are only $39. You get access to every theme on elegantthemes.com for $39.
Heres a few more options that I have not tried:
classifiedstheme.com
Templatic.com > Classifieds Theme
Sofa Opnpress Publishing Platform on Theme Forest
Good luck!
