Yeah, they have ones with 1 TB HDD, and some with Windows installed too. Besides these guys, I routinely search for surplus equipment all the time

Yeah, they have lots of stuff if you search around the site. Probably other surplus sites or there too with good deals

You can get a Dell Optiplex 7020/9020 SFF i5 16GB RAM No HDD from the Michigan State Surplus. For me shipping was about $25 for three of them.