akpackfan,
I'm only 5'8 and I have been riding Ultras for many years. I think your inseam might have more to do with anything than actual height. My inseam is only 29 inches, so I've had to make a few adaptations along the way to insure handling the bike at stops, etc.
The big thing is getting down low enough with your feet. I have never lowered a bike, never had to. What I do is immediately get a Mustang seat because the smooth touring saddle will sit you lower, then take the new seat to a upholstery shop that I have used for years and have them take in the area on either side of the seat's tongue area. Doing that lets me get my thighs closer in, thus extending my leg reach enough that handling an Ultra is not a problem. Seat looks like it came from the factory that way, and is very comfortable for me.
Also, the rider backrest on the Mustang touring seats will allow you to sit up straighter and that also helps with extending the leg reach.
On my last Mustang seat purchase, I decided to go with the pillow look so it would match the passenger backrest on the tourpak. The pillow look does sit you up higher, so when I took it to the upholstery shop for the thigh area reduction, I also had them reduce the padding in the seat area. Works like a charm, and it all matches now.