I have bought Edsal metal shelving and I think its good quality at a decent price. I know Sears and Sams and Amazon sell it.
Consider what will be on the shelves? How much weight and how deep.
The shelf I got at Sams has wood (particle board??) shelves but its held on all 4 sides by metal.
You may end up with one type of shelving for really heavy weight stuff and another for medium weight stuff.
Of course guys never have any light weight stuff.