Where would I get the best rate to change around £500? Should I send it to a bank account out there instead? Which method? (I'm new to this, it was dirt cheap to send money from Dubai, doesn't seem so from the UK).

Has anyone used the online sites such as M&S, Postoffice etc. for changing pounds into pesos? I found this site with a better rate, anyone used it?

http://www.foreign-currency.com/

Thanks.