I want to add the laser to my CNC but

You didn’t say too much about your current dust collector or shop environment. If you are in a garage and can open doors/windows it might be fine.

I have a dust collector that vents to the outside, and just having that on anywhere near the laser will remove most of the smoke. You don’t need a special “smoke boot” for the laser.

BTW, cutting generates a lot of smoke, but engraving not so much, so it also depends on what you are doing with the laser.

My dust collector is loud, so I prefer to open the doors and use a 30" wall fan to blow the air by the machine and out the door.

There are some ideas for you in this thread too. Vacuum honeycomb table for laser cutting