First: Your set up sounds excellent to me as is. 
I wouldn't add any other cichlids to it
As far as Rainbows and other dithers, I'd try rosy barbs. The tiger barbs have worked well for me BUT my cichlids are a male gt and a female JD. With that Loisellei in there I'd want a bigger barb, but not too big like a tinfoil barb.
Rosy barbs get great color and might fit in there perfectly. I'd think the Tiger barbs would be snacks for a larger fish like Loisellei especially a male
Any Pics
Good luck
I wouldn't add any other cichlids to itAs far as Rainbows and other dithers, I'd try rosy barbs. The tiger barbs have worked well for me BUT my cichlids are a male gt and a female JD. With that Loisellei in there I'd want a bigger barb, but not too big like a tinfoil barb.
Rosy barbs get great color and might fit in there perfectly. I'd think the Tiger barbs would be snacks for a larger fish like Loisellei especially a male
Any Pics
Good luck
