Greetings John,
You'll find a selection of Aikido dvds at
www.budovideos.com. Please click
here to access the DVD section.
The Ken Ota dvds are ok. He teaches Ki Aikido in the Santa Barbara, CA area.
As for format, DVD is excellent for technical videos as it allows for crystal clear step by step playback. Chapter stops also allow you to find a particular section quickly.
Best,
Jake McKee