Start with your conditions, then match features to suit.
Quick guide:
Stone content: choose auto-reset legs for stony ground to reduce stoppages; shear-bolt protection suits lighter, cleaner land.
Soil type and residue: pick the mouldboard shape that will invert and bury trash cleanly in your soil.
Tractor power and width: number of bodies and working width must match the available horsepower. As a rough rule, allow about 20–30 hp per furrow on 14–16" bodies.