Glodigger,
I'll get some pics of the bike with the fatboy handle bars so you can see how it looks. Just as an FYI, I'm more about comfort than looks, so other people might not care for the change.
When Craig (hubby) did my handlebars, he had to splice the wires. He then put in plugs so that if he has to do other work he can just unplug them and they are done (he's an electrical engineer so knows about the colors on the wires, etc.). We did not have to extend any of the cables, but he said we may have had to do so if he didn't do the conversion. If you want more details, let me know and I'll see if he can help me get pictures, but can't do it until we replace the headlight assembly (because of the location). I might be able to get him to write out some details for me that I can get to you.
As far as seats, I prefer the mustang seats as well, but love the stock seat with the brown leather. I might go with another mustang seat, but would definitely have it re-upholstered, because the brown leather really stands out.
Good luck on the run and assuming you are military, may I say thank you for your service, whether it be past or present.