Good solo kensai kit:
Pale Green Ioun Stone
Ring of Gaxx
Ring of Protection +2 (SoA) /3 ( ToB)
Boots of Speed
Cloak of the Sewers (melee) /Clock of Mirroring (for mage battles)
Girdle of xxx Strength (Frost SoA, Fire ToB)
Shield Amulet/Amulet of Seradine/Amulet of cheta speed
This combo gives a base AC of -2 assuming DEX of 18. Applying the shield amulet sets this to -8 which isn't at all bad to say you're not wearing any armour. That then stays for 5 turns, so equip the amulet of cheta speed to cast improved haste, and then equip the amulet of Seradine to get the MR and saving throw bonuses.
For weapons, the roleplay factor should see a kensai using a 2-Handed sword. For powergaming purposes, dual wielding will produce a higher amount of damage each round, but if you really want to see some high damage values, use the staff of the ram from ToB and the kensai can hit for a max of 55 damage each hit which is truly awesome.
BTW I hope you're brave enough to try it on insane ALL THE WAY
