The Monk uses light Clothing/Armor, my recomendation is the Xanthous Set without the Crown. You can also leave the upper body free. Therefore, this build has really low poise and will need a lot of vigor to be playable.
The given Stats can be altered of course and are only an orientation of what would work well. The Faith/Attunement are for those who wish to use some miracles for extra healing etc.
For his choice of weapons, the Warrior Monk is a proud Martial Artist und will use the Caestus and later on, the Demon's Fist (Boss Weapon). As backup, he will use long range melee weapons like the Glaive, Spear/Winged Spear, Drang Twinspears or the really cool looking Black Knight Glaive.
Concerning Rings, I would go with Chloranthy, Ring of Favor, Wolf Ring and any other that pleses your Playstyle.
A small reminder at last: this is aimed to be a cosplay build mainly. While being playable und fun in both pve and pvp, this is by far not an optimal build and has designated weaknesses. I did this build for DkS2 and it was a lot of fun there too :)