Metal Gamin
Metal Gamin are the most tanky models you can buy for 4ss. They aren't speedy at Wk4, but they are great Scheme runners if you can get them there, because they will stand in a place and are hard for your opponent to remove. Their basic attack is not overly powerful, but can add Burning which makes it pretty good. If you are playing against Constructs, their (0) is absolutely amazing.