In reply to IMA: These days, agents seem quite happy to sting potential renters for several hundred quid on top of deposits and the like to do things like background checks etc. Prices vary so if I were you, I would ring up prospective agents before you hit the ground to find out what their charges are and then target the cheapest. All agents are shit so don't feel you will be getting a substandard service by going for the cheapest option. If you can find people letting privately through local papers or the internet, that is certainly going to be the cheapest option.
Finally, never sign or hand over cash for a flat at the actual flat address as there are various scams attached to this. Always do the paperwork at the landlord's house or office.
Good luck - I don't envy you.
PS Oh - and when you move in, check the inventory like a hawk and photograph absolutely everything including the state of the windows preferably with the agent present. Feel free to update the inventory about dirty windows or blemishes on the carpets / floor etc. Having part of your deposit retained for things like window cleaning and other non-essential maintainance jobs that will not be done is also sadly quite common.