For a nice lookin driver backrest look at some of the selection of seats Custom Chrome have with removable Rider and Pillion backrest that are built into the seat itself, not bolted to the bike with any hardware.
Not sure the brand name - cant remember right now - but search thier site maybe. Or try Le Pera.
You can switch out the back rail of the Deluxe Seat for a Springer backrail, and then add a springer backrest. Can stay on while 2 up or solo.
ALso keeps the bike looking just like it is, only difference is a double rail on the springer, versus a single on the deluxe.
I did this on my wifes Deluxe...Looks great, and she loves the back support
Remember, Springer backrest comes in 2 sizes...short, and tall..Tall is much better
If you need adjustment forward, yuou can add a spacer under the center bar of the rail...this will move the backrest forward in a tilting motion. I added a 3/4 inch chrome spacer for the wife, but she is short, I am 6 ft, and did not need it adjusted at all from original.