Customization classified type website

Hi all
I am seeking knowledge as to where I might find a template, free or otherwise which performs the following functions.

I wish to establish a business based on a website which lists items for sale and items wanted. It applies to a very specific segment in the business world and would not be open to people wanting to sell or buy anything outside that sector.

Clients using the site would be required to register and log in with a password. The can then post their item for sale or item wanted with pictures. Registration function on the site is thus required with auto e mail response etc.

The site would have to be able to log all visits and what was looked at, posted etc. and by who. It would have to count hits.

All responses to items for sale or wanted would be directed through the administrator. Any sales would be by direct payment from buyer to seller, ie. not Paypal

The site would need functionality to add categories and to generate regular e mails to members with new postings for sale or wanted etc.

Ease of use for the template is important. I am completely new to website building.

I would be very grateful for any advice