Hi Phil
Alloy Wheel protectors I.M.O. are a waste of money & look a bugger, as the wheel collects more crud. I can recommend tyres that have bump protectors (that's a small un-obtrusive lip), these are the way to go. My alloys are close curb rims too, which look ok but have the disadvantage of near scrapes with high kerb-stones. There are a few brands of tyres that have these bump/wheel protectors built-in you just have to shop around, it's a very personal choice. You can PM me if you need any useful web-links to learn what's best for your car & how you drive it. PS I'm not in the tyre industry but I know a fair bit about them.
Cheers BarryT