Very few people have replaced the insert on the stock FW.
I have heard of this once of twice bot not sure who does it.
Do a search and you might find the threads on it.
You can have the stocker turned once if it isn't to damaged.
Most people go with the Fidanza FW with the replaceable friction plate.
If you REALLY want to do it right the first time:
fidanza flywheel
26 spl input shaft
one piece bearing retainer
fiorre or maximum motorsports firewall adjuster and quadrant
always use an OEM ford replcement cabe if needed
The clutch really depends on how much power you are making (or plan on making) and your driving habbits
If 600-650 rwhp (or less) is yor goal, a quality single disk will be sufficient.
Everyone has thier oppinions of what clutch is the best. I've had a spec3, dfx, mcleod, and my current one is a custom full faced high clamp, high rev clutch from promotion powertrain. I have been pushing it to its limits for the past two years or so and it kas been taking it like a champ.
Compared to the DFX or the spec3, it is not as much of an on off swith. It does not engage as aggressivly asa puck style clutch.
Give Walt or Wally a call at promotionpowertrain.com/ and they will set you up with the right clutch for your car
If your planning on pushing 650+, Id start thinking about a twin disk set up ,($$$$$). With 677/649, and hard dragstip launches I know that I'm on the edge of what a single disk can handle, and I'm planning on adding atleast another 100-150HP (maybe more:-D) in the not too distant future. I know that a twin disk is in my future.
If the friction surface can be replaced on the stock flyhweel I don't understand why it's not a more popular option? I guess the fact you have to ship it off and wait to get it back....
The stock flywheel is a nice piece though, I don't think there are any gains to be had in replacing it with a Fidanza other than the convenience factor...