Anyone saying that the KA/SR are the same as an RB20 shifter are purely speculating and should stop. The KA/SR shifter fits RB20DE just fine but they are not a 100% bolt in for a DET. I read up on the subject awhile ago so I can't give you all the details but I know that if you want to use a KA/SR shifter it requires you to remove parts (internal shift arm?) from the KA/SR and install it into your RB20det tranny which is more work that it's worth unless you have the parts lying around and your tranny is removed from the car.
The only shifter available for sale currently would be a Nismo solid shifter for RB20DET, which is always a special order part from Japan.
I'm not going to link you to ebay auctions, but i'm sure you can find it.
