Correct, Authorize.net is intended for USA users, although in some cases it can be used for UK, Canada and Australia.
DT Register already uses PayPal Website Payments Standard... which is just a fancy name for a regular paypal account
. When DT Register redirects to PayPal, the user has both options. They can login to their paypal account, or they can choose to pay without an account. To the left of the login is this:
Don't have a PayPal account?
Use your credit card or bank account (where available). Continue
"Continue" is a link to proceed without a paypal account.
Regarding implementing a different payment gateway, we are planning on adding other payment options soon, but have a couple other higher priority items that are in production already. Hoping to be able to look at other payment options in another month or so. Thanks.