Home for Redz

I wanna upgrade my tank.I can do it anytime but the problem lies within one thing-My two bettas.

What internet says:
''Betta can't be put together''

What betta breeder says:
''Depending on the characters of the betta,it is sometime possible to put male bettas together.I have 4 male bettas together and they go along well.''

So which is more reliable.In any case,Redz can't be put together with Terrance.Redz will attack him even though they are in different tank.Sheez...

I need to find Redz a new home...