Not sure about US but UK Surplus clothing is the best. I have tropic trousers and they’re not only super comfortable, they’re the most practical with insane amount of pockets and will survive whatever i do in them… and they cost 1/4 of a store brand jeans.

Tops are also super cheap but you can get away with camo pants, camo long sleeves makes you stand out. But the bug repellant treated tops are awesome in the summer.