Am I right in thinking you are situated down under? If so I am currently working on a PHP ecommerce site in Oz. We are using Payment Express http://www.paymentexpress.com/ . As other have pointed out they offer several integration options:
- Iframe/re-direct - This is quite straight forwards to integrate. You just post a bunch of stuff to them and they will post back a bunch of stuff to say it the transaction completed or not
- webservice - Uses an xml webservice which is pretty well documented and dead easy to implement. I guess this option is a little more complex than the iframe option but it allows for more control over what happens during the transactions. But you need to be a little more wary of how process people credit card details
The client actually chose Payment express not us directly so my recommendations are based on actually coding the interface. Their specs and sample code are freely available on their website without registering.
Hope you find this helpful.
