Your first picture isn't going to work with those uv LEDs, they need at least 3.5V or else they'll be even dimmer.

. Use a 3 or 4 aa/aaa battery pack along with that 100 ohm wiring.
It is ok to have spot lights on your helmet, be sure to aim them downward. Aiming them straight forward would be bad. People don't like being blinded and it makes for bad pictures.
People still like using really bright LEDs, but have been moving more toward diffused LEDs, or ultra bright LEDs with a diffuser. Blinding people is a big concern.
On your led website have a look at the Millicandela/Lumen rating, that is the perceived brightness. The violet and uv LEDs, says n/a...
Did you notice this?