Any box will do, if it’s a thick box, then yes a magnetic pickup is the way to go? Anything thicker than 1/4”won’t give too much acoustic value? Another option is to thin the box from the non- printed side which can be quite labor intensive, depending on your tools? Most boxes are thinner on the bottom than they are on the top, so those boxes are generally good to use as the soundboard? Camacho boxes are also thick, about 1/2” thick in some places, so don’t feel so bad?