there used to be a spread betting company that offered automated trading: futuresbetting.com. unfortunately they are out of business since march, so at the moment you´d have to use a "real broker".
A good way to get started with automated trading is through a platform called Collective2 (http://www.collective2.com), which lists many systems for equities, forex, etc., which can automatically link to your brokerage account. This is particularly useful since you can launch a simulation account to give an auto-system a try without risking money.
I'd be curious if youdon't mind my asking on the difference you found between your sucess in automatic mode vs. screen watching. For example did the best Profit Factor in automatic mode turn out to be 1.5 while in screen watching mode it's 2 or 3 time better?