Clear wood finish with minimal color/sheen change?
It seems like a new finish of any kind is going to be somewhat at odds with a weathered, distressed look.  That said...

A water based urethane finish should change the color less than an oil based one, but there will still be a change.  A final coat of satin sheen finish over the initial coats might be simpler than the steel wool and less likely to change the texture of the distressed wood.  You may want to use fewer than normal coats of finish, or thin the finish so that it doesn't build up as much as one might normally want on a "new" piece of furniture.

Some sample boards would definitely be the way to go here.