Well, since Superchips came out with the SCT, they may have discountied those type of chips but the SCT is basically a Superchip that has a custom program by an SCT dealer/vendor instead of having tunes come from Superchips themselves.
Not sure about the Diablesport chips but I had the Diablosport Delta chip for my Zetec and it didn't remove the speed limiter even thought on the ECU code list it said that it should. It was a hit/miss with those chips.
Check out this chip review. Click here
As far as the Duratec, you need to get the ECU flashed. No service port for a chip like the Zetecs.