Serpaes are nasty little fin nippers, i wouldnt advise keeping these with any fish with long or delicate fins.
Of the others any combination of any of your choices would work though there could be problems with the discus which can be annoyingly fussy little things, if they decide the BGK is too scarey for them to share a tank with you will have to remove it or them before they stress themselves to death.
Of the others any combination of any of your choices would work though there could be problems with the discus which can be annoyingly fussy little things, if they decide the BGK is too scarey for them to share a tank with you will have to remove it or them before they stress themselves to death.