Widex, Oticon, and Phonak are all solid manufacturers, so I would not lose any sleep over that aspect. Does number of channels matter? Short answer yes, as that allows for finer gain adjustments. Long answer, more channels does not necessarily mean more benefit, particularly when you are looking at premium level technology versus advanced i.e. “one step down” technology. That being said, the models you have mentioned are the basic technology levels of those manufacturers. However, I tend to be pretty optimistic about basic technology so long as the fitting is right. That being said, just considering software, the Widex Moment 110 has six fitting bands, Oticon Zircon 2 has twelve, and the Phonak Lumity L30 has twelve.
Phonak’s Naida devices, available as L30, are their power behind-the-ear devices.
The rechargeable PR or size 13-battery SP should suffice. The fitting range of the SP skews more severe than the PR, so I might steer that way.