These Flowerhorns are a man made hybrid,two fishes that originate from Central America,in most cases the main fish used in this hybridization is the Trimaculatum,this is often crossed with the Synspilum or firehead cichlid as it is often refered too,both fish are extremely beautiful but their dispositions leave much to be desired,especially the former.....i wouldnt take the risk but its down to the individual, also whether that person can afford it from a financial point of view if it goes horribly wrong.
In my eyes such fish don't belong in a tank with such a majestic creature as a Stingray but each to their own hey!