I got one of those exact routers from Amazon very recently, and while I have not set up the VPN on it yet, the unit has performed very well, and the WiFi coverage in my house and on my property has been excellent. The 5Ghz band really screams! The bottleneck for internet connectivity on most devices is my actual cable modem connection, which tops out at about 115Mb/s. So the data rates provided by this new router are probably overkill.
But one of the things that is supposed to be good about this router is that it has powerful processors and quite a bit of RAM. That is important when hosting a VPN so that the encryption and decryption can happen quickly and not slow down the traffic passing through these "tunnels".
The older VPN router you were given is likely not nearly as powerful, and thus might slow data throughput down far more than these new units will.
It is also easy to block individual devices from accessing the internet, so all of my cameras are blocked. Thus, they can only talk to devices on my local network, and that includes (of course) the PC that I have set up to run
Blue Iris. Once I get the VPN set up, I'll be able to access Blue Iris via the VPN remotely, and of course, that's the whole point of having a router that can do the VPN.
Your NVR will be doing for you what my Blue Iris PC is doing in my setup. So the router VPN setup will probably be pretty much the same for you and I.
I'm learning about this as I get time, myself, so I can't offer any direct step-by-step advice yet. But as I get it working, I may be able to be helpful.
The main thing I'd say to you right now is that I agree with what others have posted:
Retire your existing router, and don't bother with the old one you were given.
Buy a new one (the one you linked to is what I've got, but the one
@catcamstar suggested is apparently an even fancier one). Then use that new router as your only router. That way, things are easy to set up and will do what you want without the problems a separate router for your VPN might create.
Yes, that means retiring some existing gear, but sometimes it's a lot less hassle in the long run to get a gadget that does exactly what you want. That extra expense pays off in saving your time and working better. Plus, we'll have access to the knowledge of other folks on here who are doing the same things using the same routers in case we end up with questions.