Like ks1g said PBSF equivalent or better. Any "tail light" isn't bright enough. You want something visible in daylight. I haven't found a Turbo Superflash but that's what I'd get. Then get a good battery charger and rechargeable batteries so that it's not the end of the world if you forget to turn one off and need fresh batteries.

Lime yellow vest/jacket on you identifies you as a person but honestly a bright strobe does make a difference during the day. There are a variety of BRIGHT LED headlamps powered by 3or 4 AAA batteries that can be set on strobe. If you're going for visibility get a BRIGHT light, not any light. Princeton Tec Eos is good, Petzl TikkaXp2, Black Diamond Storm. The Tikka Xp2 has a hellaciously good strobe with a focused or dispersing lens. The Storm has a very bright light and the strobe is with two side leds. Tec Eos has a lower speed strobe and not quite as bright but overall a good headlamp. I'll rotate the headlamp upward so it doesn't blind others at night. I can see it reflecting off of highways signs 75yds away.