If you're not worried about the cost difference, keep the stainless with the band color you prefer. My preference is white. 😉
The stainless might get scratched, but less chance it will dent or develop gouges. The sapphire crystal won't scratch as easily (if at all) as the ion glass will. Yes, you can buy screen protectors and cases, but I think that's ridiculous for a watch and the cost of those would reduce the difference in price between the two models anyway. The sport may look sportier, but the stainless absolutely looks classier.