@adam Thanks.
@tyler recommended the same, so that's probably what I'll go with (if I can find one).
The Xeigu x6200 is also attractive, a little more than the K1 recommended by @vandys, but more expensive (2x!) than the Yaesu.
Probably less durable, but I *think* you can run Linux (and thus js8call) from a microsd card using the built-in display, so that might eliminate the need for a tablet all together.
But with durability and cost being the top priorities, the FT-817ND seems to win out.