Building a Website which can search various databases which are stored on the site

I'm wanting to build a website which can be used to analyse databases which I upload to the site using a search functions which can search different fields which the databases i'd like to add to the site examples include Email address, Username, Name (first and last)... I'd like users to be able to register to the website and pay a monthly fee using bitcoin to use the service. There is a similar site to this which is basically what I want making called [login to view URL] I'd also need a function where you can submit your username/email and it will be removed from the sites list of information after you confirm it with a link. I would also need functions such as a captcha to stop overuse of the system and also a timer between a users commands on the search function