rogueguineapig: If you can't find the gray disks, use an older Mac to install 10.6.3 onto an external drive and then run the 10.6.8 combo updater on that system. This will give a definitive answer on whether or not it's possible without them.
Kappy: Numerous threads on these boards have mentioned this.
1. Yes, it does.
2. Use a program such as the Disk Utility, Carbon Copy Cloner, or SuperDuper to move it to a blank partition on the internal drive.