Steel?
 

So im wanting to build a front bumper and I have no idea where I should buy steel from. How much I would need or a estimated cost.

I wanna build something like c4x4's bumper. But change a couple things.

Scrap yard is the cheapest, but have to look thru a bunch to find what you want. Fabricating machine shops usually have what you need in stock and will cut to size for you.