Thanks Nicolas and Kevin for your responses and information. My apologies too for the lapse in communication. It's vacation season in the US and I had taken a short holiday.
Actually, I checked in with my client and he is out of the office as well until next week. I had contacted him to ask if he could track down BofA to see if there were alternatives to using cybersource. I'm still awaiting word on that. Also he would need to approve any costs for creating the payment module.
For a bit of background, this client already has a Joomla 1.5 site with ecommerce that I set up for him 3 years ago. It currently runs Virtuemart v1.4 and has SSL set up. I'm upgrading the site to the newest Joomla and looking for cart system options. He doesn't care much for Virtuemart, and the newest version doesn't seem mature enough in it's development to continue using it anyway. I like the features available in HikaShop and see it as a solid product. So it would be wonderful if it could process payments through cybersource, "closing the circle."
I had installed a 3rd party Cybersource payment module in VM when we first launched the J1.5 site. My recollection is that I needed to ask his web host about "soap" so it's possibly that technology is what is used in that module. I do know that the card validation process happens in real time, and is a single last step in the 4-step checkout process (order confirmation, shipping method, payment input, approval). The client subsequently completes the charge on the card when he ships the order. That is done within his client portal at Cybersource.
If it would be helpful, I could send the VM module php file if it would help to determine which method this was using.
Finally, until I hear from my client I'm unable to commit to authorizing any work. That said, it would be helpful to know what the approximate costs might be. Would you be able to give me a rough estimate (I'm sure this will be the client's first question)?
Thanks.