> With most Work for Hire agreements in the US, the client owns the code..
I think you have this backwards. By default the creator owns the code. (unless you agree in writing otherwise) Some exceptions I am aware of (IANAL) is if you are an employee, then the employer owns the code by default.
Under the "work for hire" clause, I think (?) that if you are commissioned for the work as an individual, you should have the copyright by default but may not have the copyright based on agreements made. But if you are commissioned as a business entity, your business entity would own the copyright. (again, unless explicitly agreed otherwise)
If someone else can chime here, as I may be wrong on this.