In 3.0, there was Sword and Fist semi-Complete book: had a few Ki using Prc.Monks use it. Ninjas use it. Has Ki ever been extensively detailed, in 3.5e?
I am, as a long and probably unrewarding bit of homebrewing, folding "Ki" into the Magic of Incarnum rules.
Its actually looking pretty good, overall, but it IS tedious work.