That's right, no way to get a good DS module. Ford stopped using them after 1985 (Duraspark I and II). If it has EFI of any kind it is a Duraspark III and uses an entirely different type of module. The DS III uses a TFI module and coil, entirely different from the previous models. What you mostly see now is the DS II. DS I was used 73-75 and had a conventional cap and wires, DS II introduced the big cap and positive locking wires. The control boxes for the two are slightly different.
See Duraspark Upgrade
The last thing mentioned in this article is a new performance module that plugs into the existing DS II distributor. You can use that instead of the HEI module if you want. I don't know if the HEI module adjusts timing for easier starts or not, but I wouldn't be surprised if it did.
You might be able to get a better Duraspark module from Chrysler, or all places! The Jeep Grand Wagoneer used Duraspark II through 1991. Try a module from the local Jeep dealer. Of course they may just repackage an aftermarket box now, who knows?