Nothing you can do construction wise will assist you with your noise problem. The big bucks you invest might only muffle your decible reading by fractions and the foot steps or stomps will not be less heard.
This is a terrible experience when someone is so dis respectful and could care less of others privacy, sound is an envasion of privacy.
since you cannot reason with him and nothing else works, then is there something that you can do to equally distract him? Then if it distracts him then you can bargan on "i will do this if you will not do this or visa versa".
Upstairs noise is hard to stop on downstairs tenants.