What exactly are you trying to do? Start accepting credit cards directly for purchases on your website or set up a processing service similar to paypal? Or something in the middle? Or neither? LOL...You're very vague!
I wouldn't bother unless you have bags of cash. You'd need dedicated hosting, a high quality SSL like this one. You will also need a merchant account so you would have to have an excellent business plan to show your bank as setting up a CC processor would be high-risk. PLUS depending on what country you live in you might need a licence. Australia for example you'd need an Australian Financial Services Licence.
You can initially have a tieup with some bank and you can carry onn with your own brand name....percentage will be paid to you bt the bank...