Only focus on Tek Stegs, best place to find them is Lunar biome on Genesis although they are littered about on all maps.
Focus taming for high hp. A max lvl 180 with 35+ points in hp will be a great tame if it comes out with high 40s or low 50s in hp.
These are great for rocket running deathwalls and soaking tricky locations.
A must have for any pvp tribe