Maybe try Gap? My DS likes their pants. Lots of cargo pant options but suggest you show your DC to be sure they match what he's thinking:
https://www.gap.com/browse/men/pants?cid=80799&nav=meganav%3AMen%3ACategories%3APants#pageId=0&style=1181124&mlink=80799,M_PANTS_EBB_CARGO