The MT4 trading platform is available to download from most of the best forex brokers worldwide and you can even start trading with the Z Trader FX EA on a free demo account to verify its performance just keep in mind that the price feeds on demo account can be different from real account and thus potentially give different spreads, slippage and commissions.
For the best possible trading conditions and to save on trading costs, I personally always prefer to use an ECN forex broker.
Due to its fully automated nature, the Z Trader FX EA is suitable for beginner and advanced traders, you simply set it up in a few minutes using the provided instructions, set a sensible lot size and you can then let it trade for you whilst checking back on its progress.
The EA trades on the EURUSD major currency pair which tends to have some of the lowest spreads due to the vast amount of liquidity, especially when using an ECN forex broker.
The EA package includes instructions, support and a refund policy. You should consider that no system is guaranteed to perform exactly like it does with historical data as historical results are just a means to indicate future performance.