Try this link Tomo:
http://www.aerostich.com/catalog/US/Aerostich-Sheepskin-Saddle-Pads-p-16998.html for sheepskin.
Have you considered the Aqua-aire? Dollar for dollar I challenge anyone to come up with a seat, cushion, whatever that does what the aqua-aire did for 39.90 US. Here is their website:
http://www.aqua-aire.com/ I was able to log about 130miles on the aqua-aire cushion two weeks ago.
The cushion is black and disappears once you plant your arse on same. Normally I can go about 30 miles before the butt bones start hurting and about 50 miles before they go numb. I just don't have any padding back there guys! Anyway I didn't start feeling any discomfort at all until about 100 miles and it was very minor. I alternate between the aqua-aire and stock seat to try and confuse my butt. It really helps to alternate. I just pack it away in my beetle bags as it folds easily.
No I don't work for aqua-aire. At 39.90 US I doubt they can afford any kick backs to me.
WARNING: Do not take pressure off of cushion while at speed. It will probably fly off. I plan on coming up with a way to fasten it under the seat. I think aqua-aire is missing a golden opportunity not customizing these cushions for different applications. They are one size fits all but fortunately they fit well on cruiser seats.