In Pop 1.21 some of the weapons can be found by looking for the hidden chests in Valonbray and Rane.
Some are found on the Noldor. Some can very rarely be found in Shops.
In 2.0.. the chests will not work like that..
There are four tiers of weapons.
Normal - pretty much all iron based weapons.
Exceptional - found on high end troops and often in the marketplace.
Elite - Used by Noldor, specialty Heroes and some very elite troops. Very very rarely found in shops.
Legendary - only found via the quests and sometimes used by Signature Heroes.. they may, on an off chance, drop one but I would not count on it. There are five base weapons, a Bow, an Axe, a Two handed Sword, A one handed Sword and a Glaive. They can be "Upgraded" to one of three directions.. A Wind Weapon represented by a sapphire, which is very very fast; a Blood Weapon represented by a ruby, which seeks blood and does much more damage, and a Soul Weapon represented by an Emerald that is slightly faster and does just a bit more damage.