Perfect Speaker

Requirements for a perfect speaker for my 2 speaker (FR + Sub) setup.

1. Paper cone.
2. Between 5" to 6", or 120mm to 150mm diameter.
3. High Efficiency of above 94 dB/W.
4. Frequency response of at least 150 Hz through to 20 kHz.
5. (Optional) AlNiCo Magnet.

Possible Contenders

1. Lowther DX45/55/65
2. Lowther A45/A55
3. Supravox 165GMF (but a little shy of 20 kHz response)
4. Supravox 165-2000 (With Alnico)
5. Fostex 167E, Sigma 167E, 166E
6. Fostex F120A (too low efficiency, but AlNiCo)