The IMT (Interoperability Matrix Tool) on http://now.netapp.com/matrix lists some iSCSI HBA's that are officially supported.
The HBA needs to have a bootable BIOS extension.
For Management you may still need to install the Microsoft iSCSI Service from the s/w Initiator package.
Note that, when using Snapdrive you can't take Snapshots of the boot disk, and
you absolutely need to put in the IP Address of the Filer that is reachable from
a normal network interface, since you can't use the iSCSI HBA for normal network traffic,
since to the system it looks like a SCSI adapter (afaik).
There are also MB chipsets that can use the iSCSI Boot Initiator from Microsoft.
If you already have an Bootable iSCSI HBA, you need to go into the BIOS to setup the Filer's
IP Address as a target. Make sure you have a windows or windows_gpt style LUN mapped to 0
to an igroup with the iSCSI HBA's initiator iqn and you can install the operating system
from a CD/DVD, after a reboot.
Cheers,
O.