Diy laser cutter/engraver/scorcher

[curious aardvark]

So I've pretty much figured out how produce a profile to con simplify 3d into using a bolt on laser as an engraver/leather scorcher.
Got fed up waitig for some other bugger to produce a clip on laser engraver kit and decided to develop my own.

I can design and make attachment clips and run power from somewhere (got both mains and pc psu next to printer, still gota couple 24v connectors on the printer board as well).
I've figured out the how to line the thing up and calibrate and let s3d think it's printing a single layer plastic design and produce the design in the first place.

And that's where my current knowlege ends.

To burn a design into either wood or leather, what sort of laser do I need.
How many miliamps, and is a specific colour best for torching organic material.
If necessary I can add cooling to the bracket, I know the laser pen I had a few years back got bloody hot and could melt black plastic bags and pop balloons. But after about 10 minutes, the light got a bit 'wobbly' and you had to let it cool down.

Speed is not an issue. ie: a lower power laser that stays cool longer is just as viable as a more powerful one that heats up faster. You just adjust the how fast it moves and that's infinitely adjustable.
So really whichever one will run longer and is more cost effective is what I'm looking for.

A mate borrowed my pointer - and never gave it back so i can't use it as a test.

If I can get this working I can put together a kit :-)
Hell maybe even 'launch' on kickstarter.
God knows I need the money.

But what i know about lasers you can write on the back of one of my little gears in thick marker pen :-)
That goes double for my knowlege of electronics. Which is why I've worked out how to do it long hand. The laser just needs on/off control. The rest will be done through the slicer.

So laser heads - what do I need.
And where do i get it (presumably china).

Don't suppose I can use the lasers in cd/dvdrw drives ? Got a few of them lying around that are pretty much just scrap these days..