I have the Mark Roberts AFC-100 head and 4 metre track running via their Flair software. The AFC-100 will easily take the UB G2 but suggest a short lighter lens like the UB bundle Fujinon LA16.
I also use the AFC-100 head with MRMC Polymotion Studio autotracking software on conferences. Pricey, but the best from the point of view of replicating hand-guided pan and tilt operation.