Hey, if you've got the money and the will to do it, go for it. Other than that my only thought is this:

It's my understanding that the coupe and sedan have a different dash & console (correct me if I'm wrong). That being the case, you might have a problem finishing off the bezel around the shifter on the console.

Of course, if you're going to spend that kind of money, I guess you could source the console bezel from a 5-speed 4-cyl 7th gen.

Also, someone mentioned that a 6-spd 4-door AV6 will be available at some point. Can anyone confirm this? It was my understanding that this wasn't going to happen. I know the dealers have reported demand, but Honda hasn't been forthcoming.