I haven't done it, but, there's a couple of solutions that seem to please those who do;
1. Solo Seat w/ Corbin pillion
2. Touring seat
I think that by the time you buy the Solo and hardware to mount it and then buy the Corbin, you'll be way ahead with the Touring Seat. Going with the touring seat also gives you some flexibility to go from regular SM seat to Touring with minimal effort.
As for the backrest - For rider comfort and touring usefulness the tall is better. While you're buying, get the rack at the same time. Its cheaper in the long run than if you were to buy it later and it will certainly be a welcome addition once mounted.
