The JOHN ADAMS MAESTRO brand (the blue ones) already has briefs and shorts. That's good in itself, but sometimes they're just too short. You're often on your feet for longer periods of time - not just when hiking - and then it happens: the pants chafe at the crotch. Wounds often occur. Shorts are rarely any good because the leg ends are too short and ride up.
The long underpants would be a remedy, but legs that go up to just before the knee would be better. [Similar sports underpants (e.g. from SportXX) are too expensive.]