i was going to say watch the bristlenose doesnt get to big for the tank, mine grew incredibly fast hehe. uhm khuli loaches might work thats what i have in with mine, id be careful of the bristlenose though, mine is incrediblely stroppy with the corries in my 1.2m. i would think it could be a problem as bettas dont move as fast as corries? i'v been thinking about adding some galaxy asboras to my setup but they might fin nip, same with the tetras. its a difficult thing to find tank mates for these guys, you could try platys? mine seemed to leave my betta alone when he lived in the community.