I have the same mod, but I have only built single coils in Ni200 for it. According to
Steam Engine, you need to be somewhere in the vicinity of 10/9 wrap, 3mm ID to bring a set of dualies in at .1 Ohms. I'd shoot for that, and if it winds up a skosh light, the SW might still fire it since it goes down to .05 Ohms. You know Ni200 wants spaced wraps, right? You don't build contact coils like for Kanthal? I just wind them loose on a mandrel, and push the ends together like a spring, and let them pop back out. It's worked OK so far. If you like them more regular, however, an appropriately sized machine screw will give you a spiral path to wind in. Then just unscrew the screw from the middle. Good luck, and let us know how it works.
I think you'll love the TC on the SW. I do. I crank the wattage up to about 50, to shorten the ramp time, then switch to TC mode. It will vary with juice, but I'm doing OK with mine at about 425 degrees. Good luck