Small Joomla Changes to existing system

Hi there, This is an existing website: [login to view URL] Client needs 4 changes:- * Where the white background is, an image should be placed in the background (behind the site) - effectively replacing the white background * Implement ARI Image Gallery that functions exactly like this one: [login to view URL] on the "Today's ads" page * Leave contact form on "Contact us" page, but remove the rest of the contact (such as the person's name, tel & email, etc.) * Create an article facility that will list a category of articles in thumbnail view (3 next to each other, going down as far as it needs to) for "This week's ads" and "Archived ads". When clicking on a thumbnail, the article should open. Each article normally contains the full size image of the "ad". This is very urgent and I need this done in the next 4 hours.