A custom payment page should be created for vBulletin (mockup is attached). By hitting one of the "bezahlen" buttons you should be immediately redirected to the payment provider (with the specified amount). The right box is for a free membership, which should redirect to forumhome.
Left Box is recurring subscription through PayPal or Sofortabo.
Middle Box is one time payment through AmazonPay or Paypal.
Right Box is a free membership which just redirects to the forum.
This page should be displayed after a signup.
For this to work the integration of AmazonPay is required. Please note that AmazonPay Europe Integration is different from the AmazonPay US Integration.