C6 convertibles are great, but I suggest starting with the 08 model as it came with the LS3 engine - more hp. I have the 08 roadster and love it, especially the power convertible top and 6 speed tranny. If you want an earlier model with auto tranny, remember that the 06 is a 6 speed AT and the 05 a 3 speed. You might consider the Grand Sport versions in the newer models, and you might find some under 40K. You should also select the options you really want and those that are not deal breakers. Options that are worthwhile is the dual exhaust (NPP), heads up display, interior package, wheels types, navigation, etc.
Good luck on your qwest - you should find what you want out there now that the C7s are hot items. Let us know what you find.
Barrett