Why not order springs by vehicle application? There are tons of choices... H&R, Eibach, Bav Auto, Vogtland, Lowtech, and probably a couple of others. You can rest assured, they wont ask you for your strut size
Current ride... '13 GTI Wolfsburg
BMW's from my past...
'92 535i/5 '89 325ix/5
'98 750iL '86 325(e)/5
'95 740iL '84 318i/5