parts are not so hard to get if you live in the SF bay area(maybe other metro areas are the same?). there are 2 full oem parts stores in the east bay, and an alfa salvage place out in Tracy. plus there is centerline and international for online shopping outside the area- and the aflabb. plus various alfa only shops
pound for pound its going to be more expensive, but you can get almost everything you need. some parts may have to be made depending upon the model.
If you like the 74 GTV, id also check out a JT Junior, a Giulia Sprint, and if you have just won the lottery, a GTA. I like the JT Junior for looks, its a step nose, without the dual headlights - smaller engine stock but upgradable- and you can still find some around sometimes! or import from australia or italy..
http://www.craigslist.org/sfc/car/144407454.html
http://www.craigslist.org/sfc/car/145575979.html
or get a Lancia! then you will really be cool!
http://www.craigslist.org/sfc/car/145243180.html
fix that up and you will be golden! i wish i could --