CBSubs provides the following gateways: Paypal, Paypal Pro, TwoCheckout, Authorize.net, Ogone, PostFinance, CCBill, WorldPay, AlertPay, CIC Credit Mutual, QuickPay, Moneris, eWay, TeleMoney EasyPay, offline and dummy (for testing).
Research which one will best fit your needs. Probably PayPal, Ogone, or TwoCheckout.