Hi
This is Shiva here. I am an oscommerce expert and have over 8 years experience in it.
From the project description i understand that you need an option to enable/disable product extra fields in the admin and want to choose the sort order of it. I can handle both the product list code changes, product list pages ( new products, upcomnig products, all products ) as well. Please let me know if you want to have a demo of a new oscommerce installation. I can get this done in a few hours time ( and hence the price )
Please feel free to contact me on Private messager and we can discuss the project further.
Awaiting your reply
Shiva