Well Mavrik:
I have a P-80 center mount in the F-16. It delivers 20 Lbs. of thrust measured with a tub bath vascule. It surprises me but is real. What this indicates is that I'm having not significant looses using this configuration so the tail mounted engine will have even less looses if any.
Of corse you can go with tail mounted enginne virtually in any model that accepts it.
Hope this can help.