how to create a specific catalog? any ideas?

Greetings everyone!

I need to create a catalog with product items but I’m confused how-to...

Here is a features I’d like to see in this catalog.

For public users (without registration):

1. Products items tree like Video Cards, CPU, Printers etc...

2. The ability to sort items by name, qty, price, date, specification (for example AMD CPU or INTEL based only), by the company (seller).

3. Add comments to the items.

4. Newsletter with price changes.

5. Companies catalog with their contact information.

6. Search for the products by manufacturer, price etc...

For Registered users:

1. Registration with their company/shop information.

2. Ability to add their products to the catalog sections.

3. Control prices, qty, remove items etc...


What do you guys think about it? any ideas?

Here is an example of what I’m looking for http://www.hv.ee

Thanks in advance!

You want an ecommerce solution, not MODx , try Magento

Either modx or Magento would require significant custom development effort.