Customisation of Magento extension "Customer Partner"

I am currently working on developing a Magento store (version 1.4.10) to allow customers to create simple products. I would like an extension based on the "Customer Partner" and "Customer Profile" extensions listed below: [login to view URL] [login to view URL] Currently the extenstion only works on 1.3, however I am using 1.4.10 so it MUST work on this version. I want the customer to be able to select the category and then sub-category (up to 3 levels deep) to be able to create their product. Customers should be able to select their category and then sub-categories using either a series of drop down boxes or a bullet style set of lists. Basically, I want the "Customer Partner" extension to work on Magento 1.4.10 with the addition that customers can select the category / sub-category in which they want their product to appear. I may also want further work done on this extension in the future, so making the changes in a future proof manner would be preferable.