FIS Payment Gateway?

I’m considering purchasing the WP Payments plugin, but my client’s payment gateway isn’t listed. Their gateway is FIS Global. (http://www.fisglobal.com/products-government-governmentpayments-webpayments) Is it compatible?

Also – for the add-on plugins, am I correct in assuming it is a one-time fee? Please let me know. Thanks! -c

https://wordpress.org/plugins/wp-online-store/