if ur using the w58 trans. just get a blank flywheel for it and have the 1/2JZ bolt pattern drilled in. Better yet, swap in a R154 trans and get a blank flywheel for it, then have the 1/2JZ bolt pattern drilled in.
Also, you could hit up one of the vendors on this site and see if they carry a flywheel for the application you want. If not, they could probably get one for you.