hi,
data and upload section could be easily and effectively developed as per the requirement.
User management, catalog customizaton and pricing features could be easily implemented if you are using ecommerce paltforms like magento or gocart.
Multiple data entry towards the same form could be implemented using Ajax calls.
As you prefer core php, we can do it, as per the exact needs.
we are web experts, we can handle large scale as well as small scale web projects.
you can check out our company portfolio for some of our magento works in php5 we have done, for more information.
If you want i can give client references, if needed.
We could put a time line only after exactly reviewing the project requirement analysis.
Please approve us to start the work asap.
Thanks
Neetha Webture