A complete rewire is extremely simple if you eliminate all the foo foo functions that the bike has, such as the idiot lights, front turn signals, front brake light switch, tach, etc. If you have to have all the bells and whistles, then a PDM or Wire plus is the way to go. I'm not even sure if you can get a PDM anymore. Cost wise if you do it yourself, the Wire Plus and Complete rewire come out about the same once you sell off your stock hand controls. If you have to pay someone, the complete rewire will be slightly more expensive, but not by much. I believe NAMZ quoted it in the $1500-$2000 range for a simple rewire, which puts you right there with the Wire Plus if you gotta pay someone to do it.
The Wire Plus is a band aid that you splice into the stock harness. It's not too hard to do, just tedious and if you have an issue it's an absolute bitch to troubleshoot. I have seen a few Wire Plus modules fail, I believe it's 3 now, all units I installed over the years. At least one was operator error.
Rewire takes every bit of wire out of the bike and make up a simple harness. Depending on how complex you want to make it, the job will take a few hours to a few days. It looks complicated on the surface, but once you dive into it, it's not at all hard to do. You will have to get new bars or modify the existing bars, and get new hand controls. Your Big Dog hand controls are worth big bucks, as they are getting harder and harder to find.
There is a 3rd option that some guys did using relays and aftermarket harnesses, but I know nothing about it. There are a few threads around I think.