1. Any 20+gig drive will work unless you want to upgrade to 4.0 down the road.
2. You need to obtain the BCM Image Tool (BiT) and software images. All 3.7 and newer machines shipped with the image disks. They can be purchased from Nortel or downloaded for free if you have Nortel site access.
3. If you search the forum, you will find many posts with Norton Ghost parameters that will save you from having to buy the BiT. I for one won't go that route as the BiT is only about $200.
4. To use the BiT, you need the system id and Unique ID (LAN 2 MAC address) which Nortel will use to generate an Unlock code for free (Nortel Attributable).
Or, go to your vendor and purchase a pre-programmed drive and they can reprogram your VoiceMail etc.