There is no way to integrate buy links from that gateway... unless you want to hire us to integrate that gateway completely. You could post a customization ticket with details of the gateway then we could provide a quote. Maybe you could work it into your client project.
Keep in mind, Authorize.net is already integrated. Plus in our Joomla 2.5 version, we have automated reminder AND follow up emails that you can have globally or connected to specific events... that will be sent at timeframes related to the start date of the event. Maybe you can utilize that also.