Hi! I have not worked with wordpress really, asides from some tweaking and some borrowing of the html editor a while back, but I get what it's all about and am sure I could manage the integration if necessary.
So, what I propose is to build a PHP/MySQL back-end system for uploading/managing the product catalogue and then search/listings/product pages for the results. I'd put the HTML/CSS together too.
I have made many similar projects previously, it's about two days work but I would ask for 7 days just to allow for comms back and forth (and for the weekend to pass of course) and for any integration issues to be resolved, so by next weekend this could be up and running.
I'm online for 12-14 hours each day and will reply to any messages ASAP.
=== signature ===
British living in Manila - Website Applications Developer - PHP/MySQL / HTML/CSS/JQuery/AJAX/JS / SEO - 11 years experience building front-end and back-end for a global yacht charter company. I was the sole developer for 90% of that time. I also built my own online yahtzee (dice game) community with real-time games/chat which is still fairly popular today.
Some of the projects I have completed: booking systems, search/sales/accounts/management/CMS tools, file upload handling, image processing (sizes, adding text, grafting two images etc etc), on-the-fly PDF creation, automated emails with files attached, web-scraping (with/without login spoofing), email scraping, financial/accounts calculations/reports etc