What about this?
http://www.mini-box.com/picoPSU-60-WI?sc=8&category=13NEW! PicoPSU-60-WI 6-26V DC-DC ATX power supply
- Tiniest DC-DC ATX PSU
- 60 watts / 80 watt peak
- 6-26V wide input
- 100% silent, fanless
- Over 94% efficiency
- Plugs directly into the ATX connector
- Compatible with VIA C3/C7 or Intel / AMD CPU with V(core) from 5V rail
- manufactured by mini-box.com
- ROHS compliant version
- Excellent mini-ITX PSU
Then you might use a ATX to A1200 adapter on that.