HI, seems youve exhausted the ign side of things but have you looked at the fuel side? have you changed the fuel filter this is often overlooked and can cause all the symptoms your describing.
if you have changed the fuel filter then maybe a fuel pressure test would be worthwhile.
my old mans car got progressively worse similar symptoms to yours I never gave the filter a second thought but he did, we put a new one on ran sweet as a nut after.
Ray