Lesco/JDL sells a 50lb spreader that is very "commercial". It is just a smaller version of their standard 80lb model. The only thing I don't like about it is the same thing I don't like about some other equipment that is used with fertilizer. The handlebar assembly is powder coat paint instead of stainless. In time, it WILL rust.
Other than that, it is a very sturdy spreader and could come in real handy on smaller lawns.
"The Poor Fish" circa 1930's: The Poor Fish wouldn't have been caught if he'd known enough to keep his fool mouth shut.