I also found this; no idea of minimum order.
Microsquare Magnet Wire
I'd tend to favor 130C polyurethane/nylon single coating for shorts (abrasion) resistance.
Note that the gauge is based on the rectangular dimension approximately equal to the circular diameter for that gauge, so resistance is roughly equal to round copper one gauge larger. (Round 23= 20.3 Ohms nom. /1,000 ft) The Microsquare 23 = 17.4 Ohms nom./1000 ft.)
They also have half gauge sizes in the round wire.