If I tried to tell you what size you needed, Id be guessing. All I know to do is measure the hose I.D.
As for the installation, yes, it goes in the upper radiator hose or the one that goes to the thermostat housing. Coolant comes from the thermostat to the radiator, so the screen in the filter needs to face the radiator. It only (the mesh screen) goes in one way, so if you get it wrong you'll have to turn the filter around.
Another good thing about that filter is now you can fill your radiator from there and reduce if not eliminate the need to bleed the system. Since that hose is higher on the radiator than where the radiator cap is, you can nearly eliminate all the air in the system.