Statistical arbitrage, spread arbitrage, pair trading, spread betting

I have found statistical arbitrage as a additional style of trading and I think that this idea is worth to discuss and if approved to be implemented. 
As I understand stat arb, with some sort of diversification, gives us an opportunity to stay market neutral. 
So it will be helpful if you can:
1.Analyze spreads of different pairs and find most correlated
2. Track automatically such pairs for signals
3. Automatically open trade when spread hits +-2 standard deviation (or something like this)
4.Close when spread reaches 0 or other variables. 


One of the advantages is that you can check the efficiency of such trading in SQX, as mt4 will not allow you to backtest such strategies. 
 
This idea can be extended if community decides that it is worth it. 
Thank you