I take it you are talking about the windshields, since I dont know of a 182 with a canopy. Why dont you just order them from Horizon?
Their web site shows their in stock. Part no. HAN2005 $8.00 If you meant cowl and not canopy, the blue is back-ordered, as is the red. Was told the blue cowl will be in stock the middle of May. They are $15.00. Imagine they will have red at the same time. They are gonna send it as soon as it arrives and then charge my card. Blue Cowl part no. HAN2004. Red HAN2014. Just give them that when you call.
I just bought the blue one used from someone and he had a Saito .56 in it. He had it side-mounted and he has a hole cut in the side of the cowl were the engine must of stuck out. I have the same engine, but I have it in a WM Rambler 45. I would mount it inverted if I were putting it in the 182. Its inverted in the Rambler and runs as if its mounted upright. In other words-great. It is one sweet engine. With the 182, I am gonna use TT Pro.46 side-mounted and I wont have to cut up the cowl. The manual shows an engine side-mounted. No reason why you cant mount it inverted in the Cessna. The wood engine mounts they use to supply with the plane I dont think would work. Their made for side-mounting. Just get a new engine mount if yours came with the wood one and install some blind nuts and you will be in business.

Dan