Thx for your help.
But for the plant part its gonna stay only grass 😉 im gonna try a iwagumi style tank. So very open.. but i tought the grass in the back would be cover enough for bettas. If i get it thick enough ofcourse.
Betta are predators and even if docile the others in the tank recognize them as such. Your current plan does not allow for their protection or sense of security. While eye-appealing, Iwagumi-style tanks are aquascaped for us; not for the fish.
If you have the interests of all of those in the tank you will have a separate tank for either a male or female Betta with a variety of broad- and narrow-leaved plants. However, do not house both male and female in the same tank. As OD59 noted, even in a 55 there's a good chance that eventually one will severely damage or kill the other. Even after breeding, the female is removed for just that reason.
Best of luck. The tank sounds lovely