moving pl*co??

I was thinking about moving my Pl*co...at some point in the future he will
go to the 120g but not yet, he is in a 39 high right now w/ gourami's 1
adult 3 spotted, and 2 baby three spotted....I was thinking about moving him
to my female betta tank because it is 40 long instead of high..but I don't
know if they would get along or not..
he does still have plenty of room where he is at, but if the environment
would make no difference I would rather put him in the betta tank because
there are more places for him to hang out, a bit more algae....does anyone
know or has anyone ever kept a pl*co with female betta's
Nik