The one caution with metal arch is the potential complexity of the foundation. Some of the arch buildings require some pretty serious foundations, depending on location. I think Texas will be a safe bet, but anyone with a snow load should investigate how much the foundation will cost when finished. I have friends that were shocked at the finished cost of their building. It's a nice building and went up well for them, but they certainly didn't save what they thought they were going to. When done and insulated, they wish they had built a conventional shop.