"If", you want to find the armor sets with gold letting(part of a set) then invest in Detect Hidden.
Some set pieces are in the town treasure chests,
some are dropped by certain enemies in certain areas,
some are on the map, some are in the caves.
I've found the bulk of them but there's not enough room in my Stash at the Canneroc(Webroot) house to store them all.
Neither is there enough room in my Player Inventory.
Besides, the best aromr/weapons are the ones you Mastercraft when your Blacksmithing is maxed out.
Do you understand all that?