Our cart demos show how our cart and checkout pages appear. This one for PayPal Payments Pro offers buyers a choice of paying with PayPal or a card; if you add an item to the cart, choose the card option for payment, and click Proceed to Pay, you'll see our checkout screen for card payments (we provide dummy card info you can use to test a payment here):
If you'll be using a different payment service, you can select that in the green menu near the top of the page and test the checkout experience for that. At present, our 2Checkout integration redirects to a page on 2CO's site for final entry of card details, and PayPal Payments Standard presents the card payment option (if you will accept it) on PayPal's checkout site, but all the others use pretty much the same card checkout screen embedded in our shopping cart.