For a one piece, I'd go with a Dinotte Quad Red. use one of the lower power modes at night. I use a DesignShine DS500 which is even brighter.

I don't really care what people say, I don't consider anything much less than 200 lumens to be daylight visible.

I see cyclists riding around here with lights on in the daytime, but they're not what I call daylight visible. It's more like "Hey, a cyclist. Checking out the bike....huh, is he running a light? (squints) Yeah, I think there's something flashing there below his seat."

My idea of "daylight visible" is "something caught my attention out of the corner of my eye, what is it? Hm, bright flashing light. Oh, a cyclist."

If you're not noticing the light before the cyclist, it's not bright enough.