As for the coaster I'm not too sure it's going to be as tall as Kingda Ka, think more along the lines of Rita: Queen of Speed at Alton Towers in the UK.
That said, there have been some bizarre, yet fascinating creations in Dubai such as the indoor Snowboard/ Ski Park.
I think Dubai looks fantastic. I have a friend living there who regularly posts videos and pictures that make Vegas look like a Chuck E. Cheese.
How tall is the coaster if it is taller then the king da ka the building must be huge I want to see photos.