PHL 2520 8" midrange is 100db sensitivity.
I have one and it mates well to my SA planars.http://www.phlaudio.com/datasheets/20_pdf/2520_2530.pdf
Another interesting driver I have not tried is the PHL 3450 10"
101 db senstivity, 1/2 space sensitivity 4.9%
http://www.phlaudio.com/datasheets/25_pdf/3450.pdf
/hehe