Fix Website (PHP & Ajax I think)

Hi There, Well after a terrible experience on this site, im willing to give it another go, the website in question is [login to view URL], basically its still not working, the State > Region functionality I think I have fixed, but now some of the listings are not displaying correctly in 3 columns on different browsers, fire fox seems to be fine, but chrome and others are not. I also need someone to fix the thumbnails, it looks to me (limited experience) they are just resizing the image, which is slow to load, and is also very distorted between the three levels of thumbnails. so this will need to be fixed. After running the site through the W3C Validator I can also see alot of errors, I need someone to fix, test and deliver a working website which works with all browsers, and not to delete the current data as there are paying customers listings on there. At this stage it is urgent, 7 days only, but after these visual problems are fixed there are alot of features I would like to do, PLEASE DO NOT BID if you are not an experienced programmer, I have had enough of a run around for one life time over this. I can provide individual php files as requested to so you can see the code and what is used, just ask me, I will provide full hosting access to the winning bidder.