There are two separate driver processes that you need to address. The first is the provision of NIC and storage drivers for your computer inventory, and this you have addressed in your first point.
Your second point identifies the need for your operating system image(s) to have the correct driver library to support the range of hardware that they are being deployed to. These drivers have to be available to the operating system BEFORE it starts to boot, otherwise it is highly likely that the image will blue screen well before it gets to the point of mounting the NIC and being able to access drivers on a network share (and what if the NIC driver is on the network share??)
As Pankaj indicated above, the "Deploy Anywhere" technology has been created to provide driver injection into operating system images to address this requirement. In summary therefore, the required drivers need to be in the deployed image, and correctly located so that the operating system plug and play process can find them, before the image starts to boot.
However, the way that Windows XP and Windows 7 discover drivers is different to each other. For XP, sysprep.ini needs to have every driver directory itemised. Windows 7 is more intelligent in this respect, and will recurse through a folder tree automatically when searching for drivers. I would strongly recommend that you download the Microsoft Windows Automated Installation Kit (WAIK) for each operating system you are deploying and familiarise yourself with the way that Microsoft's build technology works.
Ghost 2.5.1.2266 is Windows 7 compatible, and can make the imaging process a lot simpler, but without a decent understanding of how the build process works, you are going to end up spending a lot of time tracking down simple issues with your imaging process that will inevitably occur.
Finally, there are many articles in Connect on various aspects of imaging which I would recommend you take the time to research and read through.