The combo updated for 10.4.11 should be all you need for the system updates. After you do that update, run Software Update to see what other updates are recommended. If iTunes 7.6.1 is on that list and you're running 7.5, my recommendation would be to stay at 7.5. I am far from alone in having issues with that update (iTunes Library not seen, no way, no how) and having to reinstall 7.5.