I am making a wedding cake for my brother in August. I have made a lot of single cakes but I have never stacked a cake. I have 2 options - 1 is a 3 tier stacked cake sitting on a single stand - the other is sitting the 3 cakes individually on a stand.
I have never done a tiered cake before so I am wondering if it is advisable to do this for the first time for such an important cake? I know the 3 individual cakes will involve more work as there will be more decoration involved but I wonder would this be the safer option?
I would plan to use fondant on the cakes with a butterfly theme and I was going to do a fruit cake, carrot cake and sponge cake.
Any advice would be much appreciated.

You have plenty of time to practice. Order the SPS system, and make a small 2 tier to try it out. Either way, it is a generous gift.