Have you thought, or would you consider, an integration with CiviCRM? We use it for our constituent management and it works well, including capturing event payments. I think that the tie would be easy as the short code could be put in the civicrm event, but I am not 100% confident.
This should work out of the box with any system that can show a page that can host the shortcode. I don't know the product you're speaking of but it says it can be deployed with wordpress.
Have you thought, or would you consider, an integration with CiviCRM? We use it for our constituent management and it works well, including capturing event payments. I think that the tie would be easy as the short code could be put in the civicrm event, but I am not 100% confident.