Hi:
As long as you know where to go to the individual hardware manufacturer's websites for the W7 x64 drivers, the notebook should run just fine on W7.
HP does not support that model with drivers for W7.
The only precaution I recommend you take is to make the set of W8 recovery media before installing W7, because once you do, the recovery partition is almost certain not to work.
Please see the guide at the link below for how to do this.
The BIOS technology has changed on these new-fangled PC's with W8. You will also have to change some BIOS settings in order to install and continue to run Windows 7. Please see the info at the link below.