DC to DC converter for LED Strip

Hi Guys
Thanks for the responses so far.

Feeling a bit confused.

I am trying to make a version of: NeoPixel Painter

It uses: UBEC DC/DC Step-Down (Buck) Converter - 5V @ 3A output

They are using the same LED's.

It needs to be a very portable device so the big transformer won't work.

Any ideas?