Dude, while I commend your staunch support of the law, the OP
clearly stated in post #9 that he doesn't intend to break the law. That's good enough for me.. I have no intention of forcing people who are HOBBYISTS to provide copies of the variance paperwork before I'll answer questions here.
As far as the OP's question goes, for a ready made system with ILDA-compatible control ability this system is about the cheapest you'll find:
100mw Green DMX512 ILDA dj Laser stage light 20k - eBay (item 170522517843 end time Sep-02-10 06:27:28 PDT)
Now we're not talking about top shelf stuff here. As with everything you get what you pay for, but for use in your basement it should be just fine.
As far as control options go, the soundcard DAC is about the cheapest option there is. If you're comfortable building one, then that would be the way to go IMO. Other entry-level options include RIYA DACs and the world-class Pangolin FB3.
