I bought a Cobra L5V off ebay w/o the wrench to adjust the shaft/head.
Before I buy the actual wrench is their other tools I can use that'll fit the screw head?
I have the same driver, the screw to adjust the head is just a torx bit. Don't remember the size but you don't need the Cobra wrench to switch the head around. I just keep a torx bit and the screwdriver in my bag. You can get them at any hardware store for a couple bucks. Just take the Driver to the hardware store and show them what you need, they'll help you out.