[gavinc69]

Just found these on ebay, not sure what the turbo's are like, but they are selling them stating they are fine for 911's and engine from 1.8 to 3.0 ltr, the turbo's alone are cheap and the extra parts in the basic kit would come in handy, although a large intercooler with different shape and in/out locations would be better :

PORSCHE 944 914 911 4" T70/T3 STAGE IV 4 TURBO CHARGER : eBay Motors (item 250497250121 end time Apr-09-10 18:54:15 PDT)

Porsche 911 T3T4 TurboCharger Turbo Kit : eBay Motors (item 260551660886 end time Apr-11-10 20:00:06 PDT)

Porsche 911 T3T4 TurboCharger Turbo Kit : eBay Motors (item 270461026251 end time Mar-23-10 12:35:25 PDT)

Porsche 911 T3T4 Turbo Charger Kit : eBay Motors (item 350216993012 end time Apr-18-10 20:19:24 PDT)