I'm deciding between go for a NON-SQL engine or a regular SQL one for a document managment system for small bussines.

I have experience with firebird/sql server and found a good track of reliability (specially with firebird).

This market is full of crappy "servers" (clon-made PC, the mayority), cheap harddisk, rarely use of RAID or anything like that, some are in locations where a power-off is normal, some not have a UPS, etc... (I will include off-site auto-backup to external servers, but that no change the internal setup). (I know about end-user education about such proper setups, but is stupid depend on that, so stick to te point)

From the desing point of view, a schema-less database is the way to go for my system, but, I worry if any of the actual solutions (MongoDb, Tokyo Cabinet, etc) are like firebird and survice crash, malfunctions & abuse so data corruption is very rare.

The plan is store the office documents there & provide a central repository.