SagePay -Which One??

Hi
I am using Hikashop essential in Joomla 2.5. I want to use SagePay, but notice there are 4 options on the SagePay website for payment gateway levels of integration.

Which one does HikaShop support? Is it
1. www.sagepay.com/sage-pay-server-integration
or
2. www.sagepay.com/sage-pay-form-integration

I prefer the server option, as it offers more customer feedbacks.

Let me know before I ask my client to buy the SagePay service that HikaShop supports.

Many thanks