hehehe, how are you going to survive until then m8???
I think just 50 USD just for starters in there, in 5 dollar bills.
Thats just to get the first taxi, and emergency expences.
You just have to make shure that you have some form of Visa card or Mastercard. I dunno the way in the UK, but it should not be too hard to convert your normal ATM card. Mostly ATMs in there accept VISA.
Remember that taxis only accept hard cash.