What can i put in with a male betta?

i am getting a 5 gallon bow front what can go in with my male betta i've successfully put him in a community tank before but now that tank has to many fish for him to go in there again i'm gonna be getting a 5 gallon bow front tomorrow and he wont be put in there till monday probably what small fish could go in with him i was thinking a fancy guppie or a female betta tetra's or something else but i'm not sure let me know what u think measurments of the tank is 14 1/2W x 9 3/4D x 13 1/2H