This thread might answer some of your questions.
Yeah, my hubs are from an NA 944 not the turbo, but I don't know the years. I believe the NA discs have floating calipers, where as the turbo has solid fixed ones. I don't know what the difference is. I have lost the link now, but somewhere there is a site detailing all the different hubs.
Not sure what the increase in offset is, I should measure it really! lol..