My setup at momemt is basic, 90cm motorised dish SET UP with USALS And linux reciever.
What I need to figure out is f I went for a polar mount option , I understand now that I will need a VBox to operate the dish but is a vu+sat reciever still required or just vbox on its own?
The Vu+ / E2 boxes are just a receiver, they are capable of sending a USALS / Diseqc signal to a motor attached to the dish via the lnb cable.
The diseqc / usals motors are small units and not that strong, so generally only used on dishes upto 1.1m (some have used bigger dishes on them with various results, but in strong winds they tend to fail).
A Vbox is used to convert the USALS / Diseqc signal from 12/18v lnb power into 36v to power the actuator connected to a polar mount which uses a separate 4 core cable from the vbox to the actuator.
The 36v polar mount / actuator systems are old now and go back to the 1980's (maybe before) and are generally only used for large dishes (1.2m+) now.
In the old days, you used a receiver and a positioner to move the actuator on the dish, as time went on some receivers included the positioner box inside but it wasn't common.
The Vbox is just a simple positioner nothing more it just sends the power to drive a 36v motorised dish it does not receive any signal or connect to the tv directly.