Old rubber tires cut into strips, bits of leather and metal, some rusty chainmail, some polished bone, some treated wood, and some thick cloth like burlap. Take those materials and turn them into a suit that covers nearly your entire body--every one of those materials (with exception to maybe the burlap, but that's more for use as a backing to sew everything else onto) could more than easily stop a bite, it'd be easy as hell to find/fashion, and it just looks plain cool in the "I'm used to kicking ass, and lots of it, without looking stupid" way. That be thinkin' post-nuclear. God I love being a Wastelander. These questions are easy to answer.
The problem with armor is bulk, it will slow you down, sap you of energy faster, and make moving difficult. Take it from someone who knows, I've worn several forms of armor, chainmail, leather, plate, and military bulletproof armor.
When the outbreak happens, the best you can wear is cargo-type pants for storage and warmth when wet, wool is the best choice, a good quality t-shirt, not something thin, and a jacket to keep warm in the cold, but otherwise, armor is a bad idea, unless you wish to become one of them.
I suspect a full-body plate armor would do well if you needed to tank your way through a horde, but it would be slow and noisy.
Leather, while abundant and flexible, is still heavy, and not bite-proof, one thing most people commonly overlook is the fact that the undead will more likely than not have minimal to no pain receptors, which will allow them to use the full pressure of the jaw, which can penetrate thin sheet metal.
Copper, brass, or aluminum plating is , while in theory is good, the drawbacks are: Cutting it to the desired shape and size will take time, and create noise. The plates would need to be very thin to save on weight, which presents the problem of being very easily bent, and the last concern is noise, if the plates ever collide during movement, they would create a sound not unlike a muffled windchime.