Just use Google's shopping site at Google Product Search
to find them. I'd probably just go with Novus since it is easier to find the type of kit you need from them. Get the multi-step product which works from a coarser to a finer polish. And when Googling, it is Meguiars, not McGuiars.
Rinse the window off with a hose, then use a little soapy water with a cloth to get the dirt off. Then use whatever polish you end up with.