Yeah, I'm thinking I'll need something like the Aeon or Fibaro multi-sensor. I think I've only seen the field of view specified for one motion sensor and it was 90 degrees--not nearly as good as what's out there for motion lights. But, having sensors not at the light source could negate the need for a 270 degree sensor.
Seems like with all the buzz for HA that someone would have stuck z-wave or zigbee in a motion-sensing flood light by now. You could do some interesting, useful stuff by having these sensors all over and have their lights controlled by any other sensor, rule, etc.