It has been done but with a lot of custom fabrication to get it all to fit. You will see better results from a properly sized single turbo anyway, so yes, it would be better to have just one turbo on it.

Think about the 3rd gen RX-7 with twin turbos from the factory. Most people upgrade the twins with one single turbo that gives them much more power, so the twin turbo setup is good for spool-up time but it doesn't do much for power. A properly sized single turbo will have a good spool up time with good power results.