There is a certain way to find the best forex trading robots , but you need to walk the entire path to find it. First you need to start the manual trading and fail. Yes .. failure is a part of the process. You need to proove to yourself that manual trading leads to failure and you need matematically proven  PMO. To have such thing you need to monitor the forex market and have a lot of statistics. Only then you can build your own robots and eventyally a portfolio of robots.