MarketPress Visa/MasterCard direct gateway

Hello,

I am going to integrate custom gateway in MarketPress. As PayPal doesn't support my country, I have to options to choose from - local, PayPal-like service OR direct plastic card payment.

As to plastic cards, I have heard that they eat a lot of traffic (tell me if I am wrong), need big RAM and this kind of things.

Could you provide some info, which I should take into account about that?

Thanks,

Kote