IMO, the whole reason to buy Costa's is for the 580 lense - Glass or PLastic. Glass is the best but a little heavy . The plastic is lighter on your face but has a tendency to scratch if you drop them.
The Costa frame fit is also very important. Make sure you try them on to know what Frame best fits your face.
Maui Jim is another VERY good sunglasses with top notch lense and Customer Service.
If your budget is on the $100-140 range, I would look at Amphibia's - they make a really good product too.