rusty rotors can contribute to this, but usually they make a weird grinding noise when you are starting to slow down. also it may be that you got some defective pads. this happened to me. all the pads looked fine but when i changed the pads on the side that sqeeked the noise never came back. I would just check the rotors, make sure they are not worped, if they are fine change the pads, if they look iffy, change pads and rotors!
Yes, suspension should be first. I quote BMW by saying "Power is nothing without control"