What he means with that is:
Puffers, ALL Puffers, are fin nippers. Some to the point of stress only, others to the point of death. There is no puffer that does well in a community tank. Or rather, the other fish dont do well with a puffer around.
Its best to keep them in a species tank only, you'll be able to keep them well fed and it will harrass no other fish that way.
When getting a SA though, know that you'll have to cut its teeth more than once, which aint fun. You'll have to put them to sleep using clove oil, hoping you dont use too much, coz that will kill them... and cut their teeth
Min of 10G for 1 SA, preferable 15+