Blinkys are illegal in some Cycle using countrys.

Two Fish makes a 90 degree rubber block with 2 velcro straps, you can use any LED flashlight then.
I have a AA maglight with a 3 diode bulb conversion.

Of course you can get a 1 or 2w PB light and their clip to HB is a slide out affair , they are brighter .

those small Coin shaped batteries are expensive and are not rechargeable ..