can anyone help me stack a cake? I need 12", 10", and a 8"
The bride wants to put roses between the layers, about 1 1/2" opening, so do I use hidden pillars, with dowels to support the layers and just set the to top layers on a drum on top of the pillars? It is all made of fondant.

If you are planning to use the Wilton hidden pillars, you won't need dowels. The pilars go down into the cake and hold the plate for the next cake up. Just cut the pilars to the length you need (base cake + gap for flowers). The wilton plates snap into the hollow pillars. Everything would get assembled on site.

You can also look into the SPS system which has a very sturdy pilar & plate structure for stacked cakes. There are longer pillars that can be used for the look you are going for. Global Sugar Arts carries SPS.

HTH

Kristy