I can also recommend propertyfinder for mortgages, and depending where in Dubai, PH Property as agents who also have a good conveyancing team.
My tips for the buying process would be;
Always get the seller to apply for and show his mortgage liability letter before signing a contract. I've got burnt twice when the sellers mortgage is far greater than he declared. He will have to re-apply for it again before transfer.
Always get the seller to sign the contract or MOU first.
Don't make any cheques in the agents name, such as the 10% deposit, as they will cash the cheque early and take their commission up front
Get the agent to pay for the conveyancing fee out of their 2%, or at least some of the costs.