I restored a 1959 Fiat suicide door sunroof as a step to getting my current 1972 911T Targa after a long Porsche dry spell.
The are the motor guys
http://www.pbseng.com
This is the best source of parts in the US.
http://www.fiatplus.com/theco.htm
Then the is always ebay.
Good Luck, it was a great little family car that always attracted attention.