Customer Login, online database, CRM?

Hi, not sure if anyone can help, but I figured this would be the best place to start!

I build a few websites, and a guy I know who’s a good friend has asked if I can build him a website where people can log in, register they have a remote control car, controller, and battery set (for example), and on the other side, other people log in and can search for a remote control car, or battery, or a combo of any of the above.

What this would do is register the ‘assets’ (for want of a better word), in e table, and then my friend would run a report (or something) that shows possible matches. Then he’s manually get in touch with the seller and buyer etc.

This isn’t about buying and selling btu the concept is the easiest way I can describe it! Otherwise I’d just suggest he uses ebay 😀

Anyhow, does anyone know of a plugin or theme I could use to do this for him please?

Thanks!!
PS I used the word CRM, not really sure if that is the correct term, sorry.