Joomla Expert Needed to set up site

I have set up a site but need some help with it using joomla.

I need a site that the structure is similar to pph/ebay, I'm a designer so the design bit/logo etc is fine. i just need a basic CMS system, using joomla that will allow people to register and upload their own details.
This is a new venture so the person we select would have to sign a confidentiality agreement, there is also not much money involved, however we are willing to pay once the site is up and running and generating some income (so time is of the essence really), or perhaps we could come to an arrangement regarding payment i.e. shares (remember facebook did it).

I appreciate that this is a long shot for the people that use pph to do something on the cheap/cheap/free but if we could have any help we would definitely reward you in the future. Even if someone has a template (similar to ebay/pph style) that they could give/direct us to we would very much appreciate it.

Thanks in advance