That wire is the size I use for my
coils. It works good for the lower resistances, though you may want a 34 or 36 gauge if you like high resistance
coils. There's limited room inside the coil areas in these; winding a 3+ ohm coil to fit inside them might be difficult. Nevertheless, I have been able to comfortably fit a 7/6 wrap for 3 ohms in Kanger T2, which is about the same diameter coil area.
Can't comment on the silica, but I'm sure Stormy's has it. They get 3 bucks for a couple feet, your choice of diameters. I use cotton yarn, boiled. Wind my coil around a 2.75 mm OD fine thread screw to get a real nice wrap. Unscrew the coil off of the screw, and then simply pull 8 strands through the coil. Assemble and secure connections, cut wicks to length, and you're good to go. With a 4/3wrap you should end up with about 1.8 to 1.9 ohms, which works great on an ego. With cotton wicks and a good sized, sturdy coil, you can easily take it to 8 watts or higher should you desire.