Select the membership option you want. You will notice there are two of each with different payment options...payment via Paypal or payment via Nochex. Both are secure payment processors and both will accept credit cards (you don't need to sign up for a Paypal or Nochex account). If for any reason you have problem with one payment option, try the other one.
IMPORTANT NOTE: You don't need to join Paypal in order to pay by card using the Paypal option. When you get to the Paypal payments page, ignore 'Login to Paypal' and look on the bottom right hand side of page for the text that says:
'Don't have a PayPal account?
Pay with your debit or credit card as a PayPal guest
Click this link and this will enable you to pay with credit card'