For a project like that you are pretty much limited to the
Fostex 103En or a
Lowther PM 7A.
The Lowther is much more sensitive and will play much louder and is the better unit, but much more costly.
We have a thread going about time and phase coherent speakers, that basically requires a single diaphragm.
There are full range drivers that sound very good. Basically they come form three camps,
EJ Jordan designs, Fostex and Lowther. Historically the
Jordan Watts module is excellent and the Mk III probably the best of them.
I'm unaware of any other full rangers I would recommend.