Tony, X-Cart integrates with over a hundred of differemt payment gateways (see
http://help.x-cart.com/index.php?title=X-Cart:Payment_gateways_%28X-Cart_4.5,_4.6%29).
X-Payments is needed for PCI compliance when you need to take credit card through your shopping cart pages. If you are OK with hosted checkout provided by a payment gateway - you can use any such payment gateways integrated with X-Cart (see the link above).