While I can't help with a researcher working the NARA, I would like to offer a suggestion. Before you hire anyone, consider contacting NARA and requesting an index to the records of the 3rd ID. Getting that will allow you to become familiar with what's available and at a minimum, enable you to better communicate with the researcher. I'm suggesting the 3rd ID, rather than the 30th IR, because there may be files covering significant battles, lessons learned, operational instructions, etc. that involved the 30th but were created at the divisional level. I'm also basing this on my experience with the index for the 87th ID which contains available file listings for all the regiments and service troops.
You can contact the NARA here: http://www.archives....orm.html#part-b
In the section "I have a question about research and records at the NARA", chose "Records created by the United States military" in the first drop down menu. In the question box right below this, type "I would like to request an index to the records of the 30th Infantry Division during World War II." Scroll on down, complete the contact info and send it off. I've done this numerous times and have only failed to receive the index one time. They should send you a confirmation of receipt.
Let us know how you research progresses. Good Luck!