OPNsense with DSL?

I'm looking for a cheap but futureproof way to run OPNsense at my place.

So I'm looking for a DSL modem capable of running at 300 Mbits and being able to run im bridge mode, it's fine if I buy it used I just couldn't find any good recommendations as FritzBox seems to not like running in bridge mode. Being able to flash something like OpenWRT on it is a bonus.

And on the other hand I'm looking for good recommendations for the OPNsense box. Should have enough power for Wireguard and package inspection. Used ist probably preferred

Thanks in advance :)