cranks for 28 inch unicycle

What crank lengths do you prefer for 28 inch on-road cruising?

My Coker is still on the disabled list–perhaps beyond repair, so I am
experimenting with a really fine light-weight 28 inch wheel that Geoffrey made
for my Telford. Right now I have 110 cranks on it, but these may prove too
short for our steep hills. I’m tempted by the Black Widow cranks, but the
shortest is 150–and that seems too long.

Suggestions?

David Maxfield Bainbridge Island, WA