taz, more info can be found on their website, but...
ab int is for people with zero flight time and its a two year program where you recieve an associates degree in aviation science or something. Price is something like 45k+
pace is a 19-week program for people with at least a comm. liscense, at least 250 hours, and at least a 2-year college degree. Price is something like 12-15K
From what I've heard there is no difference in the likelyhood of getting hired between the programs (if anything, PACE probably has less people, so the pool of aplicants would probably be smaller)
from what you said about yourself, the ab int program would make no sense for you (I imagine you have flight time, and you'll have a college degree).
I don't think they hire instructors from their programs, because they don't provide any instructor ratings. Instructors that are hired from the outside world do get the guaranteed interview as well though, I believe.