What would be the cheapest graphics card solution to be able to run Sierra on a Mac Pro 1,1, assuming that I overcome the EFI hurdle and machine ID check? All I would be looking for is bare functionality, not gaming performance. I see these Mac Pro 1,1 machines on craigslist for $100-$150 from time to time, it would be fun to set one up as a VPN/DNS/file server/whatever. Thanks!