por ( paint over rust) paint would be better to use, but changing them would be best. last thing you want is to NEED YOUR BRAKES and not have any, they always seem to blow out when you nail the brakes real hard.
for the front you can set the jack right where the bolt for the rear sub frame bolts in, i use that all the time for the fronts. you can also put a jack stand under the front sub frame along the sides. where the lower control arms mount.
the rears by the frame mount also. billBoost37 posted some pis of his rear suspension replacement how to, shows where he put the jack stands in the rear.