Toshiba laptops are good. They used to have a reputation for being tough and less-easily damaged than other makes, I think the others have probably caught up now.
They always used to say that you couldn't be too rich or too thin. In the computing world you could add have too much memory or too much disk space. The amount you have is OK, depending upon what you are going to do with the machine. For instance, if you are doing large-scale graphics manipulation, then more memory is definitely a plus (and 4GB is OK, but not wonderful). Likewise, if you wish to store large numbers of engineering drawing PDFs, 500GB could disappear very rapidly.