Minecraft Account Sniper

We are needing a application developed that will allow users to search and view upcoming username availability on minecraft. The application will use the Mojang API for querying and caching results (It must be cached to a backend as Mojang only allows so many queries to occur per day). If a user finds a username they want to "snipe", they will have a link that will allow them to configure a snipe located beside the username when viewing the list. Upon clicking the snipe link, the system will request the user to create a account in our system. They will need to supply minecraft user authentication for Mojang so that our system will be able to attempt a name change exactly at the timestamp of when the username they are sniping becomes available. The user will need to make a paypal payment when creating the account. The system will need to validate that payment has been made in order to activate the snipe request. There are a number of other users and minecraft sniping services that might attempt to win the username. Our system will need to be the fastest, execute timely within milliseconds of username becoming available in order to win the username for the customer. There would need to be a simple customer portal (reason for having them create a account) to where they can submit a ticket and put in request for refund in case our system was unable to provide the username due to another service being faster and/or Mojang having technical issues that conflicts with the system. Thank you.