I need to make a wedding cake that has both square and round tiers. It needs to be 4 tier and the bottom tier will be square then round on top and a square on top of that and a round on the very top. It has to feed 100 people. I know that sometimes when you put a square on top of a round the edges poke out, and I want to prevent that. So does anyone have any suggestions on what size pans I should use for each tier?

6" round
8" square
12" round
14" square
This will feed more than 100, but not by much
Or you can do this, but I personally hate working with 4" tiers. I don't think it will be enough cake either.
4" round
6" square
10" round
12" square