I bought from Triumph yesterday a brand new dual seat for a roadster for the same reason, they are selling them cheap £97 inc vat, it has the socket for the rider backrest but the backrests are now obsolete so the seats are cheap. I bought one to try & if we both like it the all is good, if not i'll stick it on here! So i may have a rider gel seat for sale soon.
The Touring seat has gel pillion insert, I swear by the Air Hawk 2 pad for the rider seat ,done plenty of 800k days and recently a 1100k day no PITA , probably the old truckies barnacle butt helps