Opencart search module modification

Hi people i need a custom search module for opencart version 1.5.1, as you can see on the demo version here http://demo.opencart.com/ the search function is pretty limited ( keyword search ) i need to be able to search my Manufacture then Model of item
This can be coded into the core files or made into a module also i have a few search modules purchased through opencart here being one

http://www.opencart.com/index.php?route=extension/extension/info&extension_id=2165&filter_search=advanced%20search&page=1&sort=e.date_modified&order=DESC

if you can modify them feel free to do so

Look forward to your quotes

Regards Jimmy

Ps this job needs to be done asap