Where to buy roofing metal

Any DIY or Maybe Garden Centre or Builders Merchant.

Lowes and Home Depot are basically the same. I've found through the years that HD caters more towards construction and Lowes more towards the finishing product. (More choice of kitchen fixtures, lighting, etc.)

I'd get bids from both on materials. See which has thicker sheets.

no, not my choice -- there are roofing companies that specialize in metal roofs --- there's a LOT of work involved -- venting, etc. ....

Go with a professional -- seamed roof and NOT nailed.

There are many options out there Willie. I had the same wish, I began to investigate and discovered that there are metal roofs that are classified as energy efficient. I went to a roofing supply company and they gladly gave me advice. I wound up buying an energy efficient Barn Red metal roof, the roofing company even sent a specialist out. He measured the roof checking all of the angles etc. The roofing company took those measurements, precut and marked the material for location purposes. They also gave me a list of contractors that would install the roofing. Bottom line is this, if I had contracted with a roofing firm to do all of the work it would have cost me $23,000 to have the job done. By having the roofing supply folks precut the material and contracting for installation myself it cut the price down to $13,800. That is still not cheap, but I have had the roof now for 19 years and it looks like new, 2 years ago we had a terrible hail storm and my entire neighborhood was faced with replacing their shingle roofs, not me. It was pretty noisy while the hail was hitting the roof but that only lasted for 10-15 minutes. And but the way since I selected an energy Efficient roof, I got a credit on my income tax, I don't know if the Government still offers that but you can check it out.

Thank you