You have your forward and up vector set to the same thing (your forward vector is set to closest face normal, which won't work in surface align mode - where the up vector is the nearest normal as well).
You need to use PhysX, yes. Once you find a frame you're happy with, create a new flow and import the results of your PhysX flow using a Birth Flow operator at the specified reference frame time. Then you'll have stationary particles that are not interpenetrating, that are also not under the influence of PhysX.