I don't know which model PSPs you have but here is the easiest route it you just want to tow a little money at it. If all three PSPs are the same model then 1 kit will work for all of them.
the 1001 is gonna be the easiest but 3000s are pretty darn hard...it also helps if the 1001 has older firmware. My 1001 was already hacked when I got it so I quickly master the art of updating to the last hacked version of the firmware(unhacking it seemed like a waste)