The boy looks pretty good i hope you got read of parisites :)
Don't know anything about other fish and betta. All my 10 bettas separate. Just please research or wait until someone else will give you advice on what fish will go with betta. I really had bad experience with that. My first betta was in 10 gall with other fish that people at pet store told me will be fine together. Yes there were for first 1-2 weeks then they start chasing each other and nipped fins.
About plants i didn't know that either
Also i am trying to write it on every my post lol I suggest if you have spider plant you can use it for betta tank. I use it for long time.