Some clarifications:
1. You definitely need Vista 32 bit drivers if using the version of WinPE that ships with GSS 2.5.1.2266
2. If you have a working operating system on one of your Edge machines, check the Device ID (ie the hardware ID) of the NIC. Then make sure that the INF file of any candidate driver includes that Device ID in the list of supported devices.
3. The driver files need to include an INF, CAT and SYS file as a minimum, although it is not uncommon to find DLL files in the driver set as well. Drivers in any other form, eg EXE, need to be unpacked to extract the actual files.
4. This will only work for the Ethernet (wired) NIC. WinPE does not support wireless NICs as these require the full operating system to support the ancillaries. USB connected NICs are likewise not supported.