Otherwise do a labrynth board
that way it covers bettas, gouramis ect without have loads of different boards.
I just feel out of all the fish people keep it is the betta that gets to live a horrible life in a small container because people are not told how to look after them.
ie. when i bought rainbow i was told that he could be kept in one of those small cube tanks without heating ect, i now know that if i had done that then he would probably be dead because of all the temp ups and downs.
I dont want to pressure you into this but i just feel that bettas deserve a board all for themselves. Totally up to you though

Its not up to me, its up to the members
Without the members this board will be nothing

Gallant words Lionfishy.