Strength of Versaplanetary & PG-188

[asid61]

Versaplanetaries can take a lot more torque (around triple to quadruple). Look at the load ratings guide if you want more in-depth information on what the VP can handle.
A method that I've seen many teams use for large arms is a VP for a 100:1 or 300:1 reduction, followed by a sprocket reduction to the arm to gear down even further.
Custom gearboxes are fun, but can be very time-consuming to design and make. At the very least if you go that route, consider a 10:1 VP first stage reduction just to make your gearbox smaller.