[GlobalPlague]

Why you want to buy mod? Cant you just download the mod and start a server with it? If you are new, be sure your server will not be successful from the first time.

.sma files are files that contain the code (the functions of the plugin) - server dont need sma files. When you compile the sma file, it becomes amxx file. The amxx file is used by the server. To write sma file, you need scripting knowledge.