It is worth noting that you will need to have a quality management system in place to obtain NADCAP. AC7004 is sometimes called "AS9100 Lite". It has some portions of AS9100 removed, but still has more than ISO 9001.
Customers that truly want you to have an effective quality management system will not be satisfied with AC7004. They are not so much disturbed with the content as they are with how it is administered, by just tacking on an additional day to your NADCAP audit.
You don't want AS9110 unless you are an FAA repair station. That is what it is oriented for, and includes many things that don't fit a manufacturing organization.
If you are not already aware, NADCAP is very different from AS9100. AS9100 is a quality management system that involves the management of the whole company. Sure, it requires certain things for production control, such as first article inspection, making sure that production takes place under controlled conditions, maintaining traceability when required, and so on, but it isn't anything like NADCAP. NADCAP is manufacturing process specific. For example it you seek accreditation (not certification) for a plating operation, you will be audited to how well you follow the details to ensure the plating comes out right.
There are costs involved with obtaining and holding NADCAP accreditation, and you will need to pass them on to your customers (or go broke). Customers who don't see the need will not want to pay, but you really don't have a choice, as you need to recoup those costs.
All of my AS9100 clients that also have NADCAP tell me that NADCAP auditing is much more strict, and that it is uncommon to pass on your first and often even your second audit.
Don't go into it blindly. AS9100 may be all you really need. Find out what your potential customers want and expect.