EA monitoring 2 MT4s simultaneously

Imagine an EA which is monitoring 2 MT4s, different brokers, running simultaneously - similar monitoring / comparing prices based on miliseconds, like the MT4-MT4 trade copier. Optimal setting : one EA on each MT4s, but (1+1) 1x EA sender and 1x EA receiver on each MT4s is also acceptable. Once there is lagging price on any of those MT4s (gap in pips to be set manually), position(s) to be opened. When prices equalized, position(s) either to be closed or not closed, according to what is set. Essential requirement : instant orders executions. 

I would like to have the code "prepared" in such way, that we can add more than 2 MT4s to monitor in the future if possible. I need the miliseconds value to be adjustable as well (same as with MT4-MT4 trade copier). There should be some safety measure there as well : if the position cannot opened on the required price, then no position to be opened. For example : MaxSlippage function.

When price gap happens, EA will open trade on the lagged platform only. We need to count spread into the price comparisons. Let's have two additional options there as well : to enable/disable LONG, enable/disable SHORT. The JOB price range is just a shot ...