Bikepacking.com has a list of utility forks.
https://bikepacking.com/index/forks-...e-cage-mounts/
I know of the Niner Boost RDO MTB fork. I'm not sure about axle to crown distance but you could give Niner a call @ 877-646-3792. I think this fork is on the list noted above.
https://ninerbikes.com/collections/c...t-rdo-mtb-fork
Also try Carver.
http://carverbikes.com/parts/forks/
-Tim-
Edit: Axle to crown is 400 on the Niner fork.