I've had a link bracelet and SS watch since the first Apple Watch was released. While I suppose it CAN scratch the watch, it's not an issue. I don't see how the band can really rub up against the watch body in a way that would generate scratches.
That said, if you get a stainless watch (or any watch for that matter), be advised that it WILL accumulate scratches over time. It's unavoidable and simply goes with the territory of watch ownership. My two year old S2 has fine scratches on all sides, though not enough to notice unless you look up close. It also has a deeper knick on the bottom edge. I probably whacked my arm against something (a doorknob, edge of a table, who knows).
So the best move is simply to take a deep breath and not worry about it.
The good news is that the SS watch can be polished by yourself or a jeweler. The link bracelet can be re-brushed with a green Scotch Brite pad if done properly (I've done this at least five times). These steps won't fully eliminate blemishes but will help a lot.
Or you can get Space Black with the DLC coating, which according to most people is very hard to scratch.