I've been asked to do a stacked square wedding cake. She doesn't want any certain size. So I was needing to get a set of square cake pans. What is the sizes that you use the most when stacking squares ?
Also what brand pans do you recommend for the best squares ?
Here is a good thread on doing square cakes. It seems that Magic Line is the way to go. They are going on the top of my wish list. http://cakecentral.com/cake-decorating-ftopict-633805.html
As far as sizes, it is going to depend entirely on how big you need your cake to be. I did one last weekend that was 16, 12, 8; I've done 14, 12, 10 and I'm doing one in July that will probably be 12, 9, 6.
There are lots of beautiful cakes posted here with a 2" difference in the tiers. That would be determined by your cake. Are you going to be putting decorations on the individual tiers? If so, you probably want to go with a 4" difference.
The number of guests she expected will dictate the size of pans you'll use.
Here's the wilton wedding chart to help you determine number of total servings. http://www.wilton.com/wedding/wedding-cakes/wedding-cake-data.cfm