My toon is now lvl 13. I already found a nice magic dwarven greatsword, but my bow is only a dwarven bow with no enchantments and my armor is still leather. Every time I go back to Whiterun to sell stuff I take a look at the merchants, and I noticed they are already selling dwarven, orcish and elven stuff, but so far I haven't found any nice enchanted bow or armor.

I know better items will eventually start to appear as I reach higher levels. But my question is: Going to other towns talk with other merchants can help me to find stronger gear? Or everyone in every town sell the same stuff according to your character level?