Dating site, core site and affiliation

My client is keen to build a database hub for numerous sites to run from (affiliate from) - the sites will be dating orientated and we hope to take the best parts from all the major dating sites and build them into one system. We are looking for an EXPERIENCED company with EXPERIENCE specifically in hubbed databases (mySQL) linking through to multi-domains (affiliate sites) so that if one user registers on one site they are automatically listed on the other sites BUT if they pay for subscription then their subscription is only valid on the site they registered on. We will produce a comprehensive "wish list" of features but we need to know a ball park figure for this project. Ideally we would like ot work with a company with enough experience on a joint venutre status - us paying for 50% of the work in return for the chosen provider recieving a percentage of the profits - this is of course negotiable (note that we already have numerous sites that we can move users from in total around 2500 so a fair user base for starters). Do not list lots of sites you have developed or designed, I am only interested in specifically dating or adult friend finder type sites. This is a major project, some of our ideas are unique in this field so you will need to be flexible and adapt to our way of thinking - we are happy for you to outsource work you are unable to complete but will not pay extra for this - the price you bid is the price we pay, outsourcing comes out of your pocket. Obviously if you know of an existing system what we could utilise and adapt then please let us know, but we ul;timately need a core system which we can clone into.