I know it's been a while since you posted this ad, but if you're still looking for the parts I might be able to help out. I have two racks - an E36 325i and an E36 M3. I'm told you should avoid the Z3 rack as it'll reduce your max steering angle.
I'm also looking at a 318iC this weekend. He claims it has an LSD, should be a 4.27 if it's stock.
Can't help with the flywheel though...I hope you've found one!