I'm in the US and I'm hiring some programmers, some in the US and some not. I'd like to have them sign a standard sort of contract. They'll be hired based on an hourly wage and what they'll be working on will constantly change so I don't need a proposal in the contract. If things don't work out, I'll just have them stop working and I'll stop paying them. After some research, these are the things I think should be included:

independent contractor status: The programmer is an independent contractor and not an employee.

confidentiality and non-disclosure agreement: The programmer can not use or share my company's code.

work for hire: The programmer is not entitled to any ownership of my company and everything he creates for my company is owned exclusively by my company.

warranty of originality: The programmer will not use previously-written code that he does not have permission to use.

Did I miss anything? Is there a source for standard contract stuff like this? Should I just sign up for the $7.99/month LegalZoom contract subscription and download a bunch of their stuff that matches the above?