hi, this sounds like an interesting project. from my previous experience with EMA crossover systems, one has to consider multiple time frames in order to make the EA successful. a single time frame results in too many false entries. i would proceed with this project as follows:
1. get full specifications of proposed strategy from you (you will need to be more specific than what you have presented on freelancer.com)
2. put together a proof of concept version of the EA and send to you for feedback
3. incorporate feedback into a revised EA
4. complete the documentation and backtesting
5. send finished EA along with documentation and backtesting results to you.
i would budget on a week to complete this project. this will allow time for us to iterate back and forth a bit so that i can ensure that the EA is doing precisely what you require.
best regards,
andrew.