I'm using an Edge 1000 and also cannot see that option. I removed the device and paired it again, this time using 'Search All' and it showed as a Radar unit. However, there's not much configuration for it in the Edge 1000. In the Alert Settings page on the Edge 1000, I only get:

1. Colour Overlay: On/Off
2. Tones: On/Off
3. Vehicle Column: Right/Left

I feel it's just a bit of a waste having the light on in bright sunshine during the day! Nevertheless, this is a fantastic gadget and makes me feel a bit safer whilst cycling on the road.