Ok I have a way in which you can keep both but will include alot of work. I have seen something like this done before and I was confused at first.
So I walked into a fish shop in Croydon and walking around looked at a display tank. To my supprise in the tank was gold fish, Mixed Malawi cichlids and a yellow tang with some corals.
This is the shop if you wanted to ask questions.
www.heritageaquatics.com/index.htm
Well after the confusion I noticed there were three tanks one behind the other. Each had seperate filters and was inderpendant of the others. So yes it is sort of possible and will give the effect of the fish being in the same tank. It will mean loads of work twice the maintance and the hassle but it would look the nuts.