Get the Uchigatana early from the Swordsmaster, upgrade and use it! You can make it raw if you feel more comfortable with higher Vigor/Endurance in early game. Just get Str to 13 and Dex to 16.
Switch to Onikiri&Ubadachi ASAP when you get them and make them Sharp.
For further Weaponry, use the Winged Spear and Longbow, since they adopt best to the Ronin/Samurai Style.
You want to buff your Swords with Carthus Rouge to get Bleeds every 4-5 Hits. It will devastate most Bosses …
For Armor, I recommend Brigand Chest Armor with Conjurator Hands and Feet, for a light Field Soldier/Ronin like look. You can also use the Fire Witch Set (minus helmet), the Eastern Set (obvoiusly) or the Dragonslayer Set (minus Helmet), as they look the most like a Ronin or Samurai.
Concerning Rings, Chloranthy is a must for Melee Builds, you can also use RoF or Havel, Leo, Farron or Hornet Rings.
The 10/10 Int/Fth are for the use of simple Pyromancies like Carthus Flame Arc, Power Within or Iron Flesh.