Generally, what you are asking is a violation of the Microsoft license agreement. Depending on what country you are from, you may be breaking the law as well as those ISOs you refer to would be considered "Pirated".
Building the 'perfect' ISO is a long-term commitment and many have found it a rewarding experience to learn.
This person spent years refining the 'perfect XP DVD'.
I would recommend reading the fine tutorials found at MSFN.
For integrating update packs and hotfixes, you can read the pages here, here, or here.
For integrating drivers, may I humbly suggest our own beginners tutorial here. This tutorial is under revision currently and may be updated to rc1 status soon. Once final, it will probably be moved to the main page.
Remember, we are here to help, not help you break the law.