I’d argue that the point of this topic is very much Qubes-specific. OP is asking about a specific Qubes net setup to achieve his goal, not how to set up a single VM with tor and vpn.
VPN before tor or vice versa in whichever OS isn’t OS specific as I see it. But then…
You can always ask on the Whonix forum. I agree with @enmus that it is not Qubes specific. Qubes is merely the platform used to run a Tor+VPN configuration.