Hi,
I have a sage oracle dual boiler and planning to replace pump with a rotary one.
Any advice on rotary pump models suitable for machine would be highly appreciated.

Thanks
Ugur

It's more about where you're going to mount it that would make one type more suitable than another. Since it won't be able to fit inside the machine, just go with the larger, less expensive types. No need to buy a stainless steel, short-necked pump for $500 when a $110 rotoflow goes under the counter just as easily.
Same goes for the motor, whatever's available and not fancy.
Mount it on a rubber mat on a paving stone or something so the cabinetry doesn't become the motor's sounding board.