Seats are a constant source of discussion and opinion, and you need to find a confort solution that suits your bum and your riding style.
1. A good quality sheepskin cover can make a significant difference, and I've been down that path
2. Air Hawks are used by many riders, who reckon they are a great help. I tried one and did not get on with it, as I didn't like the squishy feel.
3. Information from Wombattle suggests that "BeadRider" can be pretty good.
4. There are various after market seat modifiers/manufacturers, which have been mentioned ST2UP, and you might want to add MJM to the list.
5. The gold standard seems to RusselDaylong, who custom make a seat to suit your weight, build and riding position. I have gone to one of these, and it's a vast improvement over the OEM seat, but I still need a break after a around 300km, as knees, back and bum combine to force me out of the seat.
Good luck on your quest to find a soultion that suits you particular needs.