In your case, provided the VPN speed is fast enough for your needs, I would get an EA6350V3 if you don't need mesh, or the EA8300 if you do want mesh some day.
They are both supported well and have relatively recent ARM SoC; they can both be found used for much less than $100 on ebay. I have a couple used EA6350V3 that I picked up for $25 each shipped on ebay. The EA8300 is a little more. There is no reason to spend more for a new router, or for a faster model - unless you need faster VPN today.
Wireguard is great. I use it from the linux desktop and on my android phone. It pulls much less battery power than OpenVPN on my phone. And of course it is much faster than OpenVPN.
It sounds like you are just starting to learn your way around OpenWrt. This is another good reason to stick with a less expensive used EA6350V3 or EA8300. You'll learn by doing and if you make a mistake and brick something, well you didn't spend that much on it to begin with.
FWIW, I started out stupidly copying tutorials myself - still do - first with dd-wrt, then I moved on to OpenWrt to have the same interface and firmware for all our home routers and AP's. I haven't lost a router yet. It's a journey, dare I say, a hobby even? Have fun with it.