ADEPTUS MECHANICUS: PTERAXII
Pteraxii Skystalkers are armed with flechette carbines, enabling them to unleash a withering storm of solid shot at their enemies from a safe distance. The unit's Alpha is instead equipped with a flechette blaster and taser goad. They offer superb anti-infantry fire support, but they also carry braces of arc grenades which they can drop among the enemy as they soar overhead.
This kit can alternatively be used to build a unit of Pteraxii Sterylizors instead, meaning that regardless of which unit you assemble, you'll end up with plenty of spare components for customising your collection.