I found a company that custom makes uphostery, and does BMW seats. Below is the link. Their prices are insane!
Here is a quote on the cost of the foam inserts to make a standard seat to sport seat:
Back pad $140.00 (each seat)
Center Bottom $110.00 (each seat)
Bottom Sides $100.00 (each seat)
That is just the foam. Get this, the leather covers for both seats is $1000.00
http://www.worlduph.com/bmw7.htm