I use wasp nano for single coil builds, i use kanthal iver my preferred SS to build as higher resistance to start and with a 2mm max 2.5mm coils i do a nice 8-16 wraps to get above a 0.5ohm resistance, i usually aim for 0.8/1.2 range and use a 510 drim tip mtl style at 18w smooth as can ve with 25mg salt nic