I just setup HII for an X1 Carbon with Win7 64 Pro as the client OS. I used the entire driver download pack from here SCCM package for Windows 7 (32-bit) and (64-bit) - ThinkPad X1 Carbon (Type 34xx) - Lenovo Support (US)
Once I built 1 laptop with the whole driver pack in there I then checked the c:\windows\lddriverstore to see which ones were selected and removed the rest to keep the library as light as possible.
I did need to create driver install software packages for the chipset drivers and hotkeys but the rest were fine with just the inf based drivers.
