I wouldn't base my desicion off of one site you found. You'll find out that these decriptions will vary. I made a mistake and bought a spotted puffer (one of the smaller puffers) and they described it as peaceful. After a week my Clown looked like he had been lunch. After further research I found out that they are semi aggressive, and may nip on fins. NOT PEACEFUL...
So my point again is don't believe the first thing you read on some site. Ask questions, and what I like doing is getting info from people that have experienced that situation first hand. So far I've made a few mistakes, but nothing that has killed any of my fish. Keep this is mind too. Do you like to throw away money? If so that's fine I guess, but these fish aren't cheap. So when I buy one for my tank I want to make sure I don't do anything that could cause it to stress out and get sick, and possibly die, or cause my other fish to get sick and possibly die as well. I have a 37gal, and there is no way I'd put the fish your asking about in my tank. Just keep asking questions...I've learned so much from this site. Good luck with your choices.