PHP optimization for auction website, PHP Pro Bid Clone

Hello everyone,

I run a small auction website that uses PHP Pro bid auction script that mainly php, java script and mysql. It's very similar to Ebay, but not optimized the way I would I like. The site needs some minor changes in order run more efficiently . The biggest problem is the image loading. The current program has the ability to upload images, but the thumbnails that are viewed on the site are all resized images of the actual pic, which creates loooong loading times. I want to give my site the functionality of creating a copy of any image a user uploads to the predefined re-sized dimensions that the site needs and store it with the other pics at the time of auction listing. The programmer will have to optimize the homepage, category pages, and single item pages. I also wish to increase the size of the default pics and text to something similiar to Ebay. Other minor changes I need are cleaning up the homepage search box, making sure the user searches are filtered down to all category levels, currently this feature is broken but it did work at one time and lastly create 3 text boxes in the selling page that will populate 3 attributes in my auction table. I don't see these changes as very complex, I just need someone who is organized, quick and efficient. Successfully development will lead to future projects on my site. Here is a demo page of what my page looks like http://www.phpprobid.com/auction-software-demo/.