Property Lead Generating Site

The concept itself is quite simple. I want to be able to build a website which collects leads, provides the ability to then moderate the submission (and add additional information), before then publishing the information to members of my site who can then buy this information. The closest similar plugin I have found advertised for sale is this - [login to view URL] It appears that the developer hasn't worked on it for sometime. It may be possible to use this as a base, and then troubleshoot his existing design - and add some additional functionality. Hopefully this would be represented in your quote. Some further details of key features; I would like the front-end of the site to integrate with OptimisePress, so I may be able to place the lead collection form in any of their templates (as you would with a mailchimp opt-in). I would also like the ability to 'hide' certain information that the lead has given, so that the lead buyers on the back-end are not able to view this. I would like to be able to add a PDF file, and up to 50 photos to the lead during 'moderation'. When moderating leads I would like to be able to specify a fixed price that a user of the site can purchase it for. I would like to integrate with multiple payment processors, and I would need some sort of post-back from the payment gateway so that if a lead is purchased it effectively goes 'out of stock' on the website so it can't be purchased twice. When users register to view prospective leads available for purchase, I would like them to be able to be able to specify a series of preferences which could then be matched with the information within leads collected - and for the site to then notify them when a lead matching their preferences becomes available. These would be fixed variables which could be collected from a drop-down list on the lead capture page, such as ; Purchase Price, Location, and Type of asset. Please could you give me an indication of the amount of work involved, an hourly rate, and whether there are any features here which would reduce the price if removed? Thanks for your time reviewing this!