Support Forum

I would like show the forum and topic headings and then when a person clicks on a topic to read it, have them be redirected to the payment page like you have it.  I have been trying to get my site to do this but it isn't working.  Where do I find this setting?  

I have set the permissions for guests to only: "Can view a list of forums and list of topics only".  But when the guest clicks on th topic link they go to the post thread and everything is blank (because they aren't logged in).  There are not getting redirected anywhere.  I would like to send them to the payment page when they click on a topic.  How do I do this?