Addition of Joomla extensions

Look at [login to view URL] It is a Joomla site. We want the following scripts to appear when you click the appropriate buttons in the top left of the site : A car sales script (Auto exp? - recommendations welcome.) A classified script (Ads manager? - recommendatin welcome.) A dating script - we have not seen a good Joomla script for this. Possible to load a non Joomla site to a subdirectory and produce in line? The scripts must be easy for users to upload. Scripts need adapting for uk (£ no $ Post code not zip)These are FREE to users so no Paypal integration required. There will not be large numbers of postings as it serves a local area. Therefore there must be a default 'browse all' option possible. The scripts must be installed on our server and a week allowed for testing.