The buffered board pictured is just one version. There are versions that have the circuitry integrated, no daughter board, so just looking for the daughter board isn't going to do it.
Also, I definitely don't agree that the earlier versions will fail. I've got many clients that don't have buffered boards that have never had an issue. If I was looking to buy though, I'd definitely lean very heavy toward a game with buffered boards. Buffered boards were created for a reason, better to have them if possible.
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Rob Anthony
Pinball Classics
http://LockWhenLit.com
Quality Board Work - In Home Service
borygard at gmail dot com