there are many options to DXB in business class from LON. The main non-stop options are BA, Virgin, Emirates and Qantas. Some other alternatives are Ethiad via Abu Dhabi and Qatar via Doha amongst numerous other. If you want to stick with one world the best business class option is probably Qatar in my opinion followed by Qantas. Qatar has brilliant lounge at Heathrow and can often have good companion fares if flying with someone. Also noticed your location is Edinburgh and you can fly direct to Doha from there with them. Emirates are a great option to and if you choose wisely using Qantas flight codes can still earn tier points and avios. Ethad have no alliance but by all accounts there new business class on the A380 is very impressive.