I have been commissioned to make a Cognac Bottle Cake in a wooden box. I haven't made a fondant cake in over a year and I have never carved a cake before so I am super nervous. I need to know how to go about doing it.

So far I know that I am going to use half 6 inch rounds to get the basic shape of the cake. but I don't know how I would ice it. Do I buttercream it laying down or buttercream it standing up then lay it down? If the cake is laying down do I still need to put a dowel in it? For the bottle neck, I was going to use a circle cutter but I am confused on how to blend the neck with the bottle. Meaning the top of the bottle is rounded but if I am using half rounds stacked that are flat how do I achieved the neck and the rounded top? I read somewhere something about using a wonder pan but do I have to do this?

Thanks in advanced for your help!!!