I need a plugin By which Members on Forum Can Start a Deal which includes admin

[h4x0r.pk]

hey everyone , Basically I am looking for a plugin for mybb Where for example IF 2 members on my forum agrees on deal with each other on some service. this type of start checkout should appear in inbox. When a user click start checkout and put another user's username and click proceed. the other user should get a notification of checkout started in inbox or notifications. And a Inbox conversation should start which involves Admins in it. For example my forum has 2 admins. SO now the Conversation should include  User 1 who started checkout , User 2 with whom the deal is to be done and 2 admins. So there any of the available admin Proceed the deal between both users. If there is any plugin available i would love to have this even if its paid. Or if someone can build a custom plugin for me i will be happy to pay.