Accepting offline/manual subscriptions

Greetings all.
Pse could anyone point me in the right direction. Need to set up a way to accept offline or manual payments for a subscription based app. So is wise to set up a form that a user who opts for this option to fill in and provide the details of the payment made in line with their subscription plan of their choice. This will create a subscription in the database but will not subscribe the user until the app admin has confirmed the payment and clicks on a button that subscribes the user and sends them an email. I am still thinking on how I can link this manual/ offline process to Braintree as Stripe is not available hereā€¦ do i make the manual ir offline option as a separate payment method or asone of the methods among those acceptable via Braintree. I have been struggling with this subscription dilemma for almost a month now. Any help would be appreciated