[Workinprogress]

The single arm loader doesn’t require that much hydraulic volume.

I used this pump. This pump is available in multiple sizes but the key feature is the shaft supports a side load (ie belt driven).
https://www.zoro.com/concentric-moto...specifications

I also used the split taper pulley. Really locked well onto the pump shaft.
https://www.surpluscenter.com/Pulleys-V-Belts/