Keep in mind that generally the installation process is not for the faint of heart. You're probably best off going with a local professional who can install it properly, but at least be sure you have an assistant if you're going to try and do it yourself.
Another good brand is
Starshield Armor.
Most you'll see use one of the several 3M vinyls available.
Keep in mind that you will probably want to remove your bumper numbers, lay down the clear bra, and place new numbers on top of the clear bra. You can order replacement numbers from Speedlab at 800-888-8945.
And do expect to replace the bra every few years of normal driving. They are there to protect the paint, but do take some abuse themselves and eventually will need replacing. Scratches are a little tough to polish out, so expect that. Nicks will stay there. But compared to an $18K paint job, they are a great option. A local owner has one on his Rainbow car and it's barely visible beyond 6-10 feet.