First off - two things
One being the embedded windows 8.1 key is OEM and can not be transferred to another PC
And since this is a new OEM PC you have the option to create a recovery drive.. Create a recovery drive..
then when the windows 10 update rolls out - update your oem core version to 10 core..
Now you have OEM 8.1 and OEM 10 core software that is non-transferable, but recorded by activation server to your pc..
then reinstall windows 8.1 core using the recovery media - upgrade to Pro through add features using the retail key - then upgrade to windows 10 pro...
you will have 4 activated windows editions ( 8.1 core, 10 core, 8.1 pro and 10 pro) with the pro version being transferable..
You will just have to create the one recovery drive and 3 other system images or custom refresh images