I got the idea for this build while responding to a request for a paladin build. Much to my surprise this hasn't been done yet (I checked the epic character builds guild). There have been Paladin/Fighter/Weapon Masters, but these use the Weapon Master levels for the improved critical multiplier and extended range, instead of for improving the AB. I don't think I saw another paladin/ weapon master build that made use of more than 10 levels of Weapon Master. At any rate, I would never play a cHA based paladin because of the low AB. Paladins can't cast offensive spells, set traps or use scrolls so the only way they can hurt an opponent is to hit them and the CHA based paladin typically has an AB that makes one wonder if he bothers to unsheath his weapon before using it.
I decided to offset the low AB for the CHA based paladin with weapon master bonuses. A typical STR based fighter will have an AB in the 40-46 range, while a CHA based paladin will have an AB in the 30-36 range. This character has an AB of 40, not great, but much better than the average CHA based paladin. In doing this, he sacrifices lay on hands and smite damage but as these are 1 shot (3 shot) deals, I don't consider giving up some power there much of a loss. Because of the attribute requirements for Weapon Master, the CON had to be left at 10, so the character only has 400 hit points. All things considered though, I think this is one the best ways to implement a high CHA paladin.
Slashing Dervish
Race Human (Subrace Aasimar)
Alignment Lawful Good
Base Attributes STR 14 DEX 13 CON 10 WIS 14 INT 14 CHA 13