i am about to start a saas based business and i use opengateway.net for my billing, it supports "PayPal Express Checkout (for Website Payments Standard users)" and "PayPal DirectPayment (for Website Payments Pro users)" i also heard of "PayPal WSPP API" my question is: if i store cc details in my server is it possible make all the transactions without making my customer go to paypal's page or website.. ? and what are my options because i find it not professional at all, to make a double registration to my client.

thank you in advance :)