You are a non leo or ccw person and you're going to carry at least two guns? Why not just get a ccw and insurance and be legal?

Anyway, as a backup an ankle rig is ok but not a fast draw rig.
The old boot leg pants work best.
A leo undercover friend carried a M637 in an ankle holster but lost it in a chase and never recovered it.
However an ankle holster before a knife in some cases.