After 4 years I finally accomplished this little project. I found some info out there is not completely correct so I thought I'd write it up.
What you need,
-20VT or other suitable wheels
-Fiat Coupe or Alfa Brembo Calipers (possibly others). I used the calipers from a 2001 916 GTV 3.0L V6
-Fiat or Alfa hub carriers / uprights (20VT, GTV, maybe others). I used 20VT. When using GTV they must be the early type as the ABS sensor changed circa 2000. You'll also need to press out the wheel bearing and hub for new items if you want to use 4x98 Fiat wheels
-20VT flexible brakes hoses, the clip to attach the hose to the strut and the hard brake pipe to the caliper.
-Complete 20VT steering rods (inner and outer ends). 20VT tie rods are 20mm shorter overall and are 14mm rather than 12mm. It would be possible to cut the 16VT rods down but new 20VT parts are cheap and they are stronger.
-Pads, disc rotors and brake fluid of your choice.
The conversion is simply a process of replacing the parts. It's fairly easy work for anyone competent on the spanners. I retained my 16VT ABS sensors which slotted straight in. Remember to bleed the clutch fluid and check or reset the bias valve afterwards. The wheel alignment needs to be set up as for a 20VT, it is different. My car fell within factory spec.
I also purchased a tool to remove the inner rack ends (see photo). I don't see how it is possible without one, unless you remove the subframe
