I would not call it a mod, it's a pre built board that you just need to add the connectors to and put in a box or in a laser.
1 for each laser that you want to control, same for any DAC (well almost, there are ways to control pairs of laser of one DAC).
I found the Laserworld laser you have and it does have DMX, but you will still have different patterns on that from the other one.
A lot of the built in patterns are a bit "cheesy" on nearly all lasers that have them. Sometimes you get a nice suprise and get a few quite good "beam show" patterns.
The way to go is to get a proper DAC and software to create and run your own designed shows and/or other peoples shows.
Onge