I think the key to a great saddle is variable density foam. Softer in the center, firmer at edges. This keeps pressure from creating those uncomfortable hot spots, esp at the tailbone, and supports the cheeks properly. I've seen lots of mod ideas online, including placing a foam insert in the original saddle to cutting out s portion of the seat pan to reduce support in the tailbone area. My wife and I both got custom saddles from Rick Mayer.
http://www.rickmayercycle.com/On the left of the linked page he has a page about foam. On that page, he states "My opinion is that a comfortable motorcycle seat is 90% fit and 10% foam. Really, a well fit seat can be constructed from solid steel and be relatively comfortable." After riding on a custom saddle, and some extremely pathetic factory ones I have to agree. It's gotta fit YOU, or it doesn't matter what it's made of. Good luck with your project!!
