I have noticed some videos on YouTube showing the soldier customisation screen with more options (e.g different suit/colours/helmet).
Is this a cheat or just an additional DLC pack I don't know about?
The extra customization options were originally a pre-order bonus for XCOM Enemy Unknown. They are now available via the Elite Soldier DLC pack.
Despite the price, this DLC is very important to obtain so that all of your soldiers can have the original X-COM "Guile" style hair.