Visiting anglers are normally welcome and you may have to pay per kilo for trout caught. Trout farms have fish-out ponds and you can buy fresh or smoked fish here, also at markets. Chile , Argentina and New Zealand have exceptionally good fishing and there are many fishing lodges that cater for fly fisherman, providing guides, transport and meals. Maybe one day you will be a customer. I carry a wire rack in my backpack for cooking on a little camp fireplace made of stones.
Aluminum foil is useful to wrap the fish to cook over hot embers.
Hot smoke cooking doesn't require any gear. Preferably hang and dry the fish beforehand. On the river bank fill a shallow hole with hot embers, cover with dry wood, then fish on a rack, cover with large leaves or damp newspaper. Don't let it burst into flames. Alternatively, just arrange your fish over a smoky campfire for an hour or so.