Just one point to make - why do you think a laser has better skin penetration? There is nothing remarkably special about the light emitted by a laser that would affect the human body any differently than an LED would. Lasers and LEDs only differ in a few aspects:
- Coherence: Lasers emit coherent light which means that the electrical and magnetic aspects of the EM propagation of all of the various photons being emitted line up in sync.
- Small emitter size: This allows lasers to be focused to a small point and stay small over long distances.
There are other technical aspects, but for most purposes, those are the only important differences. That said, you want to use a defocused laser which would act essentially like an LED with a longer coherence length. As far as I am aware, the human body would not react any differently to light with short coherence lengths vs. long coherence lengths.
As long as you can match the wavelength of the laser to that of an LED, they will be functionally the same. I can imagine a scenario where you may very well need a short bandwidth light source, so in that case, an LED would not suffice, but for that, you wouldn't want a laser diode, either.
In conclusion... it is the wavelength of the light that affects skin penetration, not whether or not it has laser in the name. I would suggest you use an LED.