The issue isn't whether the lamps will not function without the wiring harness and control box... it's that there's another level of functionality you're missing without it.
It's not a huge deal though. I'd be fine without the control box to aim the xenons upward for high-beam viewing. It's just very cool
The guy I bought mine from said he was buying a dozen pairs at a time for sale on eBay and was told by his supplier that the well was about to run dry. Porsche was going to stop making them and they would skyrocket in price.
I can't imagine Porsche would stop making them though if there's any sort of demand for them. People wreck their 996/986's from time to time and need new headlamps as well as all the guys like us who want an amber free lighting upgrade.