grinding

hello all,
I have a few questions about grinding. First off i am building a box for jumping on/off of, peddal grabs, grinding… What is the best material to put on the corners of the box for grinding? Are there pre made products that skate parks use? Is it just sheet metal bent over the corner and screwed down?

Also what peddals work best for grinding? I use oddesy shark bites and platforms with pins for all my riding but it seams that metal on metal might be a little too slick especially for just starting out with the grinding.

Any information you can give or tips on grinding itself would be greatly appreciated!

Thanks,
booger