I high speed commute and find any bike with a tombstone windshield horrible. I want to be hauling behind a batwing or sharknose...
I keep my RK under 65.

 

No! You're all wrong. You want a Royal Enfield!

 

This and make it a Road Glide if you do long distance interstate travel. Much less buffetting for the passenger.

 

Get separate bikes.

 

This.

Or take her for a couple test rides lile other people said. Find what she likes and buy that.

Happy wife happy life.

Touring frame all the way. Don't let the nay sayers thay ssybtouring suck. They are just jealous or don't have a clue.

 

 

Just get a Road Glide and your wife will be soooo happy with the ride that she will express it in ways you never knew existed........................

 

Same here. I owned 2 Sportys and a Super Glide before I got my first Touring bike. My wife probably had less than 200 miles combined on the Sportys and Super Glide. Then I switched to an Electra Glide and she was on that bike more in the first 2 weeks than she was on the others the entire time I owned them

 

Softtails, with the dual counterbalanced 'B' engines are the most vibration free Harleys (period).
If you do relatively short rides and minimizing vibration is the highest priority, look at the Heritage.

However, all M8s have counterbalanced engines, and though much smoother than an Evo, the touring bikes are not quite as smooth as the softails. So they would still be a huge improvement and you can't beat the overall comfort (for a back seat rider) of the Road King or one of the other full height touring bikes.