I read up on the work and its something I'm perfectly capable of, so I ordered the oven control wire from McMaster-Carr and I'll re-write my HES myself.
I found some old threads on Pelican (2006/2007) where guys were describing the same problems I'm having. They changed coil, TPS, Throttle Position, O2, Fuel filter/lines - none of it seemed to solve the problem. Like mine, it initially ran better but then the problem returned. Neither of the OPs did injectors or the HES. Those threads are what made me move the HES ahead of doing the coil/wires like I initially planned. I'm still going to change the fuel filter and swap the in tank parts just due to age/mileage.
I'll update with HES wire condition when I get into it (its been too wet here to work on stuff).