M.R.
This is truly a case where I'd talk with him and go with him so he can select the one he wants and will actually use the most. It would be a shame to spend the small fortune that any of those options cost, only to find that another choice might have been better for his particular needs and wants. Surprises are nice, but I really would tell him you want to get him one of these devices but want him to pick it out so he gets exactly what he'll use.