I know a lot of folks disagree with my choice and, admittedly, I have little experience locating, but, I have a pair of Koss Everywear SoloStereophones (http://www.koss.com/koss/kossweb.nsf/p?openform&pc^fs^Solo) that I find wonderful in every way. Yes, they have small gauge straight wire as opposed to a heavy coiled cord, but, they are only $19.95 and carry a lifetime warranty. The audio response is terrific, they are quite comfortable, they have an inline volume control (which I just leave on high and control from the machine) and even though they have full earcups, they do not totally block out external noises.....so you can still hear someone yelling at you to "get off their property or they will shoot!" Your local Whalemart should have them in stock.
I just chose not to spend the 'big bucks' on a 'made for locating' set. BTW, I do have two pair of the 'made for locating' headphones and I don't like the weight, audio clarity or comfort of either one.
Don't know where you are in Tenn., but, from what I have seen on this forum, you have a lot of history buried in your state.....best wishes on finding some!!
Edit: Forgot to mention that you will need a 3.5mm to 1/4" stereo adapter for the Koss headphones, also, available at Wally World.