http://www.airpowersystems.com.au/wrx/aps_turbo.htm
i'll summarize it for ya: "Non water cooled turbochargers have no place in a high performance gasoline engine application and should be avoided at all costs."
as for coolant system getting hot... not a problem with a proper radiator. Mine (not a 240) don't go above 200 unless i'm stuck going in 2nd gear.