Get the stainless steel model with the sport band and then you don't have to worry about buying screen protectors. For day to day minor scratches, the steel case can be easily polished by hand using any number of polishes or jewelers cloths as opposed to the aluminum case on the Sport which gas an anodized matte finish and cannot be "refinished" at home.
Then I recommend getting a set of $15 strap adapters and using aftermarket straps and bracelets. You'll save a ton of money and have the ability to easily change the look of the watch. The Apple straps are nice but too expensive for what they are.
Definitely. I saw a lot of great looking after market straps for thee watch. Do you think over time the $550 would be worth it because it is SS?