Here is the way to have a good modelling quality. You have two choice :

You can download the tick data from MetaQuotes :

MetaTrader > Tools > History Center > Select the currency of your choice and click on download.

Or you can import tick data from a broker like Alpari :

History Center for MetaTrader 4

You have to follow the same steps. Here you will click on import after to have downloaded the history. Note that the spreads are set on 0, you will have to modify the header of the FXT files with FXTheader :

FXTHeader - MQL4 Code Base