I would pass on the ecm8000 and get the Joe Meeks JM-27.
I have the ecm8000's and the Joe meek jm27's
The JM-27 are used a good majority of the time as my O/H's
The ecm8000's are omni and will pick up alot of the room. (But you can get good results with them as O/H's)
If you want omni mics...