Which apisto goes best with discus and rams?

[gex18]

I have a 400 litre Juwel rio aquarium with 10 discus, 2 pairs of rams, 3 whiptails and 3 zebra plecos, what apistos out of the following will be most compatible;

1) Agassizii
2) Cacatuoides
3) Manmasteri
4) Nijsseni (my favourites)

Also would two pairs or a single harem be better (the tank is 5 foot x 20" x 2 foot high)!?

 

[newworldan06]

You forgot to put tank size on CF What type of rams do you have? But i think that a trio of any of those would be fine. I favorite is Borelli, You should look into them, they are very peacful.