What does the wall being concrete have to do with anything? No matter what the wall is constructed with has no bearing on how deep a speaker is.
I personally would not make any speaker box less than 5" deep, so most any midrange driver will work.
I mentioned concrete wall as to rule out in-wall suggestions. The speakers need to be about 2" deep for LED TV; that is why I am looking for low profile mids. I am leaning towards these; they are a bit pricey though since I would need 4 drivers per speaker: