I just got a hold of the 600521 (new style) ACT flywheel that replaced the old style 600520 (I assume you had this one), and the 6puck sprung disc PN 6240508 and HD pressure plate PN MZ031. This is the exact combo sold by ACT on their website now (
https://www.advancedclutch.com/products/transmission/zx4-hdg6-hd-race-sprung-6-pad) except the disc sold is labeled PN 6240508-2, but my understanding is that the discs were never a problem.
The FW took a week to get here from
www.therpmstore.com, and the disc 6240508 (not the 6240508-2 new one) (
https://www.ebay.com/itm/193847066179) / pp (
https://www.ebay.com/itm/184602012390) a few days from ebay. You should be able to get similar ship times. Call the rpmstore and ask how long their waiting time is.
The Fidanza FW is 11ish lb and the ACT Prolite is 15.7lb (stock is 23-24ish lb I believe), with Fidanza having better heat dissipation due to aluminum construction which should technically lead to improved clutch disc life... curious how you'll find the difference to affect drivability.