I prefer the late 70's Chevelle mirrors over the second gen camaro mirrors. The A-body base has two studs and the gasket and works much better than the f-body version that uses a bracket like on the first gen camaro mirrors. Also the camaro mirror is a little shorter and I prefered the taller Chevelle mirror like Mark used on the Mule. If you need a visual I have pics of both installed.
I've had both (chevelle/camaro) on the car and then went back to stock in the end
I bought 4 sets off ebay before I found a real nice set for a fair price. The Ebay store I would recommend is called something like California Parts...but they are located elsewhere...I think they just buy a lot of California parts cars.