Ben,
the tentative timeline is to have both the Versign and Authorize.net gateways working by the end of March. This could slide a little as I just starting on the Authorize.net gateway and haven't seen the Versign gateway yet.
You could test the ADC interface to Authorize.net without a test account by passing x_Test_Request="true" with each request. For more information read the Authorize.net developers guide.(https://secure.authorize.net/docs/developersguide.pml#TESTING)
However some extra software is needed to make a connection to the ADC interface of Authorize.net from OpenACS. My advice is to wait for our release which will include a complete installation guide.
Setting up an account with the gateway of your choice is beyond the scope of the payment service contract. Follow the instructions of the choosen gateway.
