Unlike Ghost SCCM can deploy the same OS over multiple computer brands and models. We have 97 different models consisting of both Dell and HP systems. All you need to support multiple models is to just have a large driver database. The OS install will select the needed drivers if available. Also set your reference computer up with all the universal software used (Flash, Reader, Java, Office...) then capture everything in one .wim file as I have found this makes for a quicker deployment. Also make sure you get all the Microsoft updates before you capture the OS. Once everything is how you want your baseline computer to look break it off the domain and begin the capture. Once you get over the hump it is really a simple process but it is a steep learning curve when you are thrown to the wolves.
Here is a good Step-By-Step Guide to OS Deployment
http://blogs.technet.com/b/configurationmgr/archive/2009/07/27/a-step-by-step-for-using-osd-through-system-center-configuration-manager-2007.aspx And you can get the majority of your drivers from here.
http://driverpacks.net I personally have over 8 gigs of Nic, Video, Chipset and Sound drivers. Also when you’re importing your drivers separate them into categories such as Network, Video and so forth just for manageability.