One thing I have recently started doing is using my regular cake pans (2" deep) and giving it a parchment paper collar. By doing this I can make my layers 3 to 3 1/2 inches tall each which means you can get a good 7" 2 layer tier.
The way I use the collar is to cut 4" strips of parchment paper. Prepare the bottom of your pan how you normally would and then place the strips around the sides of the cake pan allowing them to stick up past top of the pan 2 inches. I use little dabs of butter to help the paper stick to the sides of the pan. If one strip is not long enough, you can use 2 strips, just be sure that the two strips overlap and are tight up against each other when you pour in your batter. Then pour in your batter until it’s about 1/2inch from the top. (I’m guessing. This will also depend on how much your batter normally rises during the baking process.) I also use flower nails upside down in the middle for a type of heating core. You will have to bake for a longer amount of time obviously, and again, that will depend on your batter somewhat.
I have only done this with smaller rounds (up to 8") and have not had to use any extra support. If you were doing three layers or a larger cake, you might need to add extra support. Maybe someone else will have more info on that. :) Hope that helps!
