I'd suggest just poking around on Amazon: (LINK)[http://www.amazon.com/b/ref=dp_bc_4?ie=UTF8&node=509304]
I quickly found quite a few shelves that support much more than 40 lbs such as the following:
Otherwise, you may need to go a more heavy duty route that spans two studs with metal bracketing, although that won't look nearly as nice. Really though the main thing you need to focus on is how you mount it to the wall. Make sure you are mounting into a stud with some nice large lag bolts.
Thank you!
I believe I got the shelves from Fry's. The brand is "Mount-It!" This is either the exact same one or very similar. https://www.amazon.com/dp/B009H9SKLQ/