Back in the day, some of us sent our seats to Spencers...
http://www.greatdaytoride.com/home.html. He was able to remove the forward slope, lower the height, and add some gel. Priced lower than a full custom or aftermarket. For me, this was enough to eliminate the forward lean (along with my bar risers). Only downside is that you lose your seat for a while (but I don't remember it taking very long to get it back).
Considering I was able to find his website for this post, seems like he's still modding seats.