For one thing, you should wait until MWSF. But in reference to the current model (which may or may not be drastically changed), only the screen and the wheel are really scratch-prone. The back, specifically the logo, can be scratched, but nowhere as easily as the chrome on the original. I don't use a case on mine and I don't have any problems with it.
It's considerably lighter and smaller than my mom's 40GB 4G, and the aluminum looks and feels very slick, much better than it does in photos. The best way for you to see this would be to compare it to the larger iPod in the Apple Store if you have access to one. The software is the same, except that the iPod has 12 hours of advertised battery life versus the mini's 8. The small storage may be your only concern, but I find that 4GB is fine for most people, because even with a larger library there is no reason to take all of it around with you at all times.
Edit: If you're concerned about eyesight, you might want to check that out. The screen on the mini is smaller and I believe the font is too.
.... So I was thinking of getting an iPod Mini. 
