Thank you for the quick reply and you input. It is so appreciated. :)
I would just use a wood dowel...you can find some at home depot...they are a lot more tall then the ones we normaly get for tiers. You don't need anything much bigger or solid...it's just to make sure everything stays in place. And your cake won't be heavy (since it's mostly dummy) just a small dowel will do the job.
I would use a drill to make the holes in the dummy and then start putting fondant on it. It might be hard to just try to put the dowel at the end if there's no holes in them.
Hope this helps
anna--it's true that the 8" has more surface but to me a smaller cake can sometimes look pin headed on the top of such a large bottomed cake--it can --it doesn't have to
i think that the decorating can absorb any kind of perspective issues either way
i prefer an 8 on top of a cake as large as this one is -- just my perception