Can I do a fresh install of Snow Leopard from external DVD drive?
According to the apple manual for installing Snow Leopard, you can use an external drive.
"To upgrade to Snow Leopard or install Snow Leopard for the first time, you must have a Mac with:
- An Intel processor
- An internal or external DVD drive, or DVD or CD Sharing
- At least 1 GB of RAM (additional RAM is recommended)"