I like to use Dukascopy as their historical data does not have any gaps in the candles or missing candles! It is a premium historical data. It is also what EA Studio uses for historical data.
FYI – What I do when trading with prop firms that does not have a demo account I will open a live account and use it to test my EAs. I then set the lot size to 0.01 lots so that the testing of EAs doesn’t change the account balance too much. I’m not suggesting this for you I am just sharing how I handle such circumstances just for your information :o)
Alan,