I use a nexus player which works great I have a wired xbox 360 controller plugged into it. They are discontinued but you can pick one up second hand pretty cheap. Someone one here said the intel compute stick is very good for liquidsky if you prefer the windows client.
Because the box runs on android I don't have the actual latency numbers and with the new version of liquidsky coming in a week or so there are a whole bunch of factors I have no idea if they'll work. I'd wait to buy until version 2 comes out and people play around with it a bit. But saying that my pc has latency at about 50ms. About 25 local and 25 network, on the nexus with a controller the latency seems to be less than that but as I said it doesn't give me actual numbers so it's just what I can notice with my naked eye