Buyers in the UAE are mostly trading companies. They buy Russian goods and sell them on: to the Persian Gulf countries, Asia and Africa. This is how metals, grain and food products, fertilizers, sawn timber and equipment are traded.
Many of these companies are registered in free economic zones. Each has a trade license listing its permitted activities, and the bank checks the goods against it. If a firm licensed for electronics pays for grain, the transfer will stall.
Ask the buyer to prepare a short note for its bank in advance: what the goods are, where they come from, where they go next and who the end recipient is. Banks in the Emirates ask these questions often, and it helps when the answer is already on file.
The Emirati side needs a basis for paying the agent rather than you. Sign a supplementary agreement to the contract that names the agent and gives its details. We will send you the text.
Dollar or dirham
The dirham is pegged to the dollar, so the buyer usually does not mind which one it pays in. For you, the difference is which agent will accept the currency now and how it will convert it. Fix the currency in the contract, and we will select the agent to match it.