Non Disclosure Form Information

Without looking at the form you would use and what your specific concerns are it's difficult to determine if the online form you found is sufficient.  I agree with the previous answer that the amount a lawyer would charge will depend on the answers to those questions as well as how broad the agreement would be.  Part of whether an online form is suitable and how much time an attorney would need to spend on this is based on how detailed you want to make the agreement.  

The question is a pretty circular one -- without looking at the form you already have, it is impossible to advise you whether that form is adequate to your intended purpose. An attorney might look at it and tell you to go ahead and use the form you've got without change, or might counsel substantial changes in it. Either way, you don't find out until you hire the attorney. Generally, the cost of involving an attorney in such a process would be a few hundred to a thousand dollars, depending on the complexity of the issues involved.