Re-modelling and site improvement

I have a live and working website.

It is Joomla based and uses a reverse auction component as a basis of how it works.

Although the site is working and running fine, there needs to be some improvements in its usability. This project is to make the following alterations.
In addition however, I expect anyone bidding on this to offer other ideas on how the site can be improved.

1. Currently users must register before they can upload their printing needs. I would like the registration and project upload to be integrated on the front page and NEATLY
so that the process is all in one. When someone visits the homepage, they can enter their printing needs, then on the next tab they enter their registration details/user profile etc. Please see ratedpeople.com for an example of this. This is KEY as I want people to easily be able to upload projects.

2. The layout of the auctions is currently a bit messy.

3. Messaging is currently in place, but we need to make sure that when someone accepts a bid, they can contact the seller appropriately.

4. Sellers and Buyers should have different areas of the site, although they can both enter eachothers. Something similar is already in place.

This project would perfectly suit a company who has worked on similar before or has a strong design team. Example websites that this one should be similar to are:

www.ratedpeople.com
www.freelancer.com

By no means do I want these copied, but they are good examples.

The site is currently free to all users, but will charge PER BID in 2013. This function is already integrated into the reverse auction component.

Please also note that all current data (users, projects etc) must remain intact. There is a deadline of 3 days for this project (Friday).