Hello.
I am deploying community poultry vaccinators in rural areas with devices to register households and record service delivery. I have read the guidance:
dhis2_android_implementation_guideline/mobile-device-specifications
I would suggest expending a bit more in devices a bit more capable as if not, depending on your program, uses might find the application buggy or slow.
Also, we always suggest getting a device to perform all the tests before buying the whole set. This should help you in evaluating in the devices does really match your set up because the guides we provide are really broad.