Hi Timmo
I joined in November (I think) and not yet a GSD owner and all I can say is research the breed and read as much as you can. Learn about the different lines and make sure you're getting a pup that has hip and elbow scores and health tests.
Working line might be too much for you to handle if you are a first time GSD owner. I was thinking the same as you in the beginning but decided to go for a dog with working/show lines.
I, like you, thought that straight back and sloped back were different but I was told on here that it's just the way they stand.
I have bored my friends and family with GSD talk and they look at me as if I am talking another language.
I am so glad that I joined this forum as I have learnt heaps and I definitely feel ready to own a GSD.
I have books, dog magazines, been watching videos, reading about raw feeding, etc.
The experts on here will tell you more. I'm still a mere pup myself really as I am still learning
Good luck with your seacrh.