It really doesn't matter what seats you use, the process is the same. Its a numbers game. How tall is the seat, how much room is there in the car, are the seats narrow enough to fit, ect.
You might want to try to adapt a set of factory seat rails to the BMW seats or modify the BMW rails to fit the car. It all depends on what will give you more space. I think someone makes a bolt in extender for the factory rails so you can push the seat back further. Might want to look into that.