67 Barracuda- Brakes and suspension on a 5000 budget- advice needed

My suggestion would be, "Let your budget be your guide". With that being said, figure where you want to start & start pricing new & used pieces. Put a Wanted Ad up on the site to see what is available through our members. Someone maybe upgrading & sell you some or all of the parts & pieces to do your upgrade. If you can't go it all at one time, first I would upgrade my brakes, second upgrade suspension & then anything else that needs to be done. All of the parts & pieces you remove should be cleaned up & put up in the For Sale section, you never know someone may be looking for what you took off for their build.