You'll find an abundance of niche opportunities in Dubai particularly if your business produces or sources up-market luxury products. This means there can be great margins to be had.
There are also big opportunities in boutique foods, education services and products, IT products and services, tourism, and anything to do with the wellness industry.
When you visit Dubai first and take a look around and see what's available. You'll see huge gaps and opportunities for things in all kinds of markets.