Having looked at the paladin class and compared it to other martial classes if still find myself looking for a way to get a similar ability without being forced to be lawful good alignment. I know there is a feet in the agc (believers hands) that lets you get it but you still have to be lg.
Any help with the search-fu would be greatly appreciated.
If you have access to the d20pfsrd site, look up the Youxia archetype package, who gains a Ki Pool, and Ki Talents every 2 levels (one of which gives Lay on Hands for 1 ki per use).
Warpriest's fervor is pretty similar.
Just for reference, the Youxia, is from the Genius Guide to Martial Archetypes by the 3rd party publisher Rogue Genius games. Their archetypes are different from paizos in that they can be added to any class by trading out a specific suite of abilities from each class (where as paizo archetypes are class specific). The concept doesnt fit neatly into pfsrd's sight, so its a little confusing how they work.
The youxia can thus be added to any class, and as mentioned one of the things you can do with it is us ki to lay on hands (including mercies).
The warpriest as mentioned also has a comparable ability in the form of fervor and can be of any alignment.