Whatever you get, it'll be outdated soon enough. Get the one you're reasonably comfortable with. When the new models come out, people will have the newer version, while you're stuck with the first generation that you paid close to $1000, including bands you bought for it, and you're hard-pressed to upgrade.
Aluminum will scratch, stainless steel will scratch, gold will scratch. Pick your poi$on.
In jewerly watch world there are ways to polish scratches in a watch's case:
Professional done polished with a special paste (different grades depending on the watch case material and how severe the scratches are) and buffing pad+Dremmel
DIY
Cape Cod flannel for SS mirror like finish
Special sanding pad for Satin finsh
I've done the DIY for my Tag Heuer watches. Very easy.
Do not know if it'll work on the Apple SS or Apple Sport
Google it