You should be able to get panels at a lumber yard or a decent home improvement store like home depot, Menard's, lowe's. But ya they probably aren't overly cheap and you also have to frame a structure tooi attach them to over the run so you will also need some lumber and hardware
@blucoondawg I wish I had talked to you before I got started!
@KDOGG331 it occurs to me that I should also mention that I live in a part of the country that has rain but no snow. You might want to look at the reviews on those panels and research them a little to make sure they can withstand your local weather. I got the idea to use them from someone who won "coop of the week" a while back; they sounded like they had done a really careful job with their materials so it seemed like a good endorsement. You could probably search for "polycarbonate roofing" here and find out some stuff, in fact.