Can someone recommend a vpn that lets me open the bitcoin and lightning ports?
You can literally do that with any VPN unless the provider mentions otherwise, you configure the settings in your router, make sure you identify the IP address in which your bitcoin core is running and make sure your make it the dedicated IP as you might need it when configuring the port, you can lock in your MAC address too and then under DHCP you can open 8333 and 9735 ports, make sure your external and internal port are the same, after all these configuration you can fire in your VPN and test whether it is connecting, if you are using a firewall it might restrict the connection, make sure you make an exception for the ports you are opening.
You can always refer to the tutorials in
bitcoin.org for all your doubts regarding bitcoin.
Edit:
Most of them allow port forwarding but since you never mentioned your VPN provider which stopped providing that feature but still logs every user details
, but with the providers that allows port forwarding it works fine and it is a simple process
.