The enforceability of any non-compete turns entirely on what state you are in. I also agree that a court would likely not find 6 months to be unreasonable. Depending on the nature of the business relationship, most non-competes with temporal terms of less than two years will be considered reasonable.
Typically, a NDA will have the following components: 1) the names of the parties; 2) what is deemed to be confidential; 3) the remedies for a breach; 4) consideration provided in exchange of non-disclosure; and 5) the term of the agreement. (More of my thoughts on NDA's here). I strongly suggest you have an attorney take a look at the agreement and let you know if there are any terms in the agreement you should challenge as being unreasonable and, therefore, subject to negotiation. Having an attorney take a look before signing it could prevent a lot of headaches down the road.