Customise Joomla component and template (JoomBri, YooTheme, Zoo)

I want to build a site that's similar to the freelancer.com kind of site. I have seen the JoomBri template which is cheap and looks to have the basic building blocks I require ([login to view URL]). It works with YooTheme templates. I like the Subway theme. I also like their Business Directory module, and think their icons are pretty cool too. All of that I can buy for: $36.99, $99.00, $49.00. Good. However, it doesn't have to be these items - that's just for a steer. I have chosen Joomla pieces as I am familiar with it, with PHP, with MySQL. However, I'm no expert. What I want is the joombri site to run off the Subway theme, and for the functionality of the site to be customised to capture: - A business directory of "service providers" (like freelancers). These service providers could be tradespeople, businesses like accountants, childcare providers, anything. Like can be found in the "yellow pages". - I don't want the businesses in the directory to be publicly visible, only the categories, quantity of businesses. - I want businesses to be able to register, and optionally buy "credits" (paypal integration and manual payments phase one, credit card integration if successful). I want to be able to review businesses prior to them being active (unless they have bought credits in which case they're immediately available). - I will have various customisations to make to the Directory fields that a business has to complete. - Categories can be defined in the directory - Categories will have "budget ranges" (e.g. <£100, <£500, <£1000, <£5000, <£10000, <£50000, £50000+) - Price to buy "leads" (which are customer-submitted jobs) will vary buy category and budget - "Customers" can post jobs, select a category (from the directory), indicate related sub-categories/skills required, describe the job, indicate the job location (possibly not their home address) upload a file, indicate a budget (from a picklist that varies per category), give a preferred timescale, and set the expiry date (time is not relevant, just date, default today+7 days). - Customer should indicate (from a pick list of reasons) why they want the job done - urgent work required, gathering information/pricing, insurance quotes, seeking best service provider. - Customer registration to capture name address post code, telephone/mobile - Customer needs to be registered/logged in to be able to submit the job (although they can start the workflow without being logged in). - When they select the category they should see how many businesses are in the category. - If the Customer has any feedback/select/decline items outstanding, they should get a pop up message on logging in, and on trying to submit further jobs. - When they submit the job, all active service providers in the category are to be notified (in phase two will do mobile SMS messaging). Service providers only see the job details, how much the lead will cost, rough location. They cannot see who posted it. In the email notification, they should be provided a link to view the job request and then be able to "buy the lead" - The job title/description is public on the site with a google map of where (only based on first 3 characters of post code) (but not who posted it) PLEASE SEE REST OF THIS IN ATTACHED FILE. THANKS.