Weapons to increase martial arts are
Punch (without a weapon)
Bo
Katana
Scimitars
Crossbows
Smoke Bomb Spell (Obury)
Some swords
Ashura (NFS)
Forged (Tanbur)
Kotetsu (NFS)
Tempest (NFS)
Also to increase your martial arts skills, max skills that increase your wisdom (Alchemy, Block, Carpentry and Martial Arts) .
If you use the Smoke Bomb spelll your efficiency with it will depend on your Martial Arts skill level. The higher it is, the more spell power you can use. For instance, at MA of 10, your Spell Power for Smoke Bomb would be 25. At MA of 90 it would be 350.
If your MA is over 90 you can cross the Ninja Master Platforms. Right now we don't have any in the game (but you can never tell).
(NFS = Not For Sale, which means we should probably give them to someone to sell or drop)