Actually, your #1 is close to what I have already:
- Platies
- Harlequin Rasboras
- Panda Cories
- Otos
I'll probably add Blue Rams and be done with this tank. With the above four species, I found the colors to be little on the "off" side - I was looking for some larger fishes to show more colors. Hopefully (German) Blue Rams will do this...
By the way, Platies like pH > 7, while the others like pH < 7. My water is at 7.2 and they seem to be ok...