I have a 2016 Deluxe and a Mustang Deluxe seat and love both. However, I would add that even though the Mustang provides great sacrum support, it doesn't really support the lumbar. If you absolutely must have a true backrest, this might be a consideration. The seat also sits you back a little, and the additional support is angled slightly backwards. So if you have a short reach then you will be leaning forward toward the bars and away from the support. I'm 6' with a 31 inch inseam and have Heli bars to pull the bars back quite a bit. In any case, this is a great forum for ideas, support, and help, and it's an incredible bike. Good luck!
Welcome to the Forum Lady rider.
The F6B is a great bike for sure, and the deluxe model would be an excellent choice If you do get an F6B, and everyone here will agree, just how much a great bike it is. The best part for me of riding the F6B is just how easy it is to steer, control, and maneuver. I had a Honda Valkyrie IS for 14+ years, and with all my years of riding such a beast, I really didn't think any other bike could replace it. But I was wrong
Good luck with your search, but do try to obtain a Matt Gray F6B. Those that have one, know they are the fastest