Puffers are very aggressive. You could go with dwarf puffers, if you do I suggest you only keep one per 10 gallons and have plenty of hiding places to block their line of sight from each other or else they will kill each other. Some people have had success with multiples in a tank or puffers in a community tank but if you want happy healthy fish I would recommend you don't try that lol. And don't believe the LFS they are just trying to sell stuff
(unless they are a rare reputable one), also +1 on Dragon's statement
EDIT: It will be extremely beneficial to you if you research the fish you want first, you will know how they behave and how they should be kept. Make sure you read up on plenty of different sites, and if the information matches then it is most likely true. Don't listen to wikipedia because anyone can edit that.