Small Business Server no 'Add Mirror' available- why?

I did my first install of Small Business Server R2 yesterday after being out of the IT field several years.
The install was on a low end IBM Xseries server with 1GB Ram 3Ghz Intel D procesor and two SATA drives 80GB each.

I partitioned the primary drive into two partitions.  A 35GB partition for the OS and remaining 45GB as free space on that drive.
Th other HD I left as 1 large formatted empty 80GB drive.

I wanted to Mirror the drive with the OS to the other drive.

I did not have the 'Add Mirror' option when I right clicked the drive in Disk Manager.  

QUESTION: I am unclear why I wasn't presented with the option to 'Add Mirror' when the second drive was equal to the primary drive and was empty formatted space.

In retrosepct, I feel it was good I didn't have that option as people don't seem to like the Windows software mirror solution.  

QUESTION 2: This basic install of SBS 2003 R2 took 4-5 solid hours to install on this system. I paused maybe 20 minutes total to get the latest NIC drivers and update the BIOS.  The media was on 5 or 6 CD's the customer supplied.  My Manager and myself were wondering why it took so long- or is this somewhat typical of a SBS install + running WIndows Updates?  It seems silly to have to feed CD's througout this time period.  Is there any way to cut down time wise on a SBS installation?  

Thanks in advance!

Dean