what ZFS pool to create

Yesterday I bought two Western Digital 1.5GB Caviar green. But this are only the drives to start the pool with. To get all my data into the pool using RAIDZ, I need to add the drive to the pool after copying the data from it.
Luckily before starting this I was trying this in the VirtualBox to have all commands ready and not mess up the real data. But it is not possible to expand a RAIDZ:

• Expand-O-Matic RAID-Z


• WHEN TO (AND NOT TO) USE RAID-Z

Sun designed/cares about ZFS in the professional environment. There you don't set up box with only a view drives and add drive after drive. This is only a scenario for the home user. This is only possible with a mirrored
So I will start with the pool with the two 1.5GB drives mirrored. After copying the first two 1GB drives I will add this mirrored to the pool.