If you have access to a +2 wis tome (or a +2 supreme tome would be better) then drop 4 points from wisdom to a starting wis of 8 (+6 item -2 stance +2 tome = 14 which is the minimum required to cast zeal... then again if you're stopping at paladin level 12, then you only need 13 wis)
Otherwise you can drop 2 from wis and 2 from int.