some of the parts you listed are less expensive on a
www.autohausaz.com, I buy most of my OEM BMW parts from them. They are a great deal. I would also change the thermostat and waterpump. Make sure you get the waterpump with the metal impellar not a plastic impellar. Good luck. I know of some DIY for doing this work on the V8, not the 4 or 6 cylinder. Pelican Parts sells a book call 101 projects to do on your 3 series. It seems to be comprehensive with lots of colored pics and diagrams. Hope this helps.