AEM-
http://www.aempower.com/
Fujita F5-
http://www.f5air.com/
Injen -
http://www.injen.com/
^^these are the 3 i can pick from the top of my head. not sure for the price of a intake for a cobalt but these same intakes for my mazda3 will cost 200$.
for warrent, i dont know how chevy runs the show but with mazda if they find a problem with ur car that relates back to the intake ur warrenty is gonzo.
sorry i cant really help u anymore than that. o btw where in ontario are u? im in woodbridge.