Maybe, if they list windows 7 drivers
I would use them. I've installed Windows 7 and Windows 8 on my two desktop PC's that have ASUS motherboards and a lot of the drivers are the same for Windows 7 and 8. They will say compatible with Windows 7 x64 and Windows 8 x64 in the description and you will get the exact same download regardless of which OS you select. My new laptop came with Windows 8 but also lists Windows 7 drivers in its downloads. Before you buy just go to the support page for the one you plan to buy and see if there are Windows 7 drivers available for it. If they are dedicated Windows 8 drivers they may not install, you'll get a this OS not supported or something similar message. You could also Google that model to see if anyone tried the OS swap and ran into problems.