Looking for simple rectangular planters for my terrace made out of steel, resin, polymer (anything not wood) for my terrace. Ideally would like something 5-6 feet in length, 2-3 feet high and 10-14 inches deep. Length and height are the most important while depth is the least -- also if I found something in the right length that I'd be willing to sacrifice my desired height. I found some at restoration hardware that I liked (and were reasonably priced