I have been wanting to play a cleric that eventually gets Planar Turning. It seems like this has happened to me before when leveling cleric, but level 17 just hit and I got into the inevitable quandary about whether to take 4 martial class levels. It is an even tougher decision this time because not only is there the extra attack but a taking a paladin level (eventually 35/1/4 CPF?) earns such crazy saving throws when base charisma is going to end up at 26.

My mind says to get the martial levels but my heart wants to stay cleric. Otherwise Implosion won't arrive until 21 and spells are generally weakened. Does anyone have thoughts or history with these matters?