To make the installation easy and to give you the maximum flexibility you should install the Merlin software on your router.
Secondly you need to find a VPN provider that has servers that are not recognized and blocked by Netflix. I don't use Hulu so I can't tell you if they are blocking VPNs.
The VPN provider must also have a server in the country where you want to obtain the video from.
I would suggest that you contact several VPN providers and ask them which of their servers if any will work. Then install their VPN app on your PC and test that you can actually stream.
If you find one that works download speeds on your router will be slower than running it on a PC, however with the router you have you should be able to get download speeds of 15 - 20 Mbps.
Finally, install the OpenVPN on your router running Merlin. This can be as simple as just uploading the ovpn file from your VPN supplier. If you think or someone tells you that PPTP or L2TP VPN will be faster than OpenVPN feel free to try it. I never noticed much/any improvement running these protocols as the encryption on a fast connection limited my speeds to 55Mbps on a 180 Mbps connection. Same result with reduced encryption but with you slower connection this might help maximize your speed.
Your AC3100 will not be the bottleneck on a 25 Mbps connection. Mine would do 60+ Mbps using AES-128-CBC encryption and SHA1 data authentication.
Take some time to read through the threads in this forum section. There are a number of discussions relating to your objective. If I'm not mistaken @Xentrk has figured out a solution for what you are trying to accomplish.
I'm running Merlins firmware, have been for a number of years. I was able to get TorGuard up and running without issue (thanks a million to Xentrkand his detailed instructions) I ran speed test and I'm hitting my full 25mbps. So far so good..