Sagepay Direct Support Uk?

Hi we must admit we are very impressed with Hikashop especially with custom fields. Just one thing i noticed is sagepay extension does it only support the re direct option or does it support sage pay direct we have quite a few customers that we our moving to this paltform

Hi,

I'm in the process of helping a client set up their SagePay account, and the application states the following:

Which system do you wish to use?
You may need to contact your shopping cart provider for advice on the Sage Pay system they have integrated with.

It then gives me three options: Form, Server or Direct. I'm a bit unsure what to select for Hikashop to use, any help would be appreciated. We are using Hikashop Business if that makes any difference.