Pfsense is a free software firewall you can install on an old desktop PC. Does everything you could ask.
You will need to get your hands dirty mind you.
I run OpenVPN on it and direct whatever traffic\devices I want down it. Has no issue at 56Mbps. Doesn't even hit 20% CPU
No problems with getting my hands dirty but not looking to add to my electricity bill either
but if it comes to that I do have an old PC and happy to re-direct its use. Thank you.