vgcea~~I've been watching this thread; it was an interesting question. I've been a hobby baker for 2 years now. Last September I did a 100th birthday cake for a wonderful woman. About 200-250 were going to attend her party. My cakes were a love gift, but the skill level needed and the mental pressure was very similar to a wedding cake.
Although I did well and was not disappointed in any aspects of the cake presentation, it was an overwhelming task. I learned a TON of stuff doing these cakes. Logistics, expense, timing, transportation, cutting, table prep, size of cake boards, prep of cake boards, having a friend to help, the sheer number of hours (especially the 24 hours before the cakes were due!), on and on and on.......
Because these cakes were my love gift, I had total control of the design, colors, flavors, everything. I was able to change aspects of the design, etc. at the last minute in order to get them finished and out the door. It would have been 100% more stressful if I'd had the necessity of adhering to a specific design (such as a bride's design).
Here's a link to my thread on Wilton.com where I have some photos and explanation of the cakes:
"MY BIGGEST CAKE PROJECT, EVER! (whew.........)"
I would suggest you identify a source where you can donate, design, transport, cut and serve a large stacked cake and make a "practice run". (You can contact local homeless centers, hospital emergency room Staff Lounges, Convalescent Staff Lounges, Police Stations, etc., anywhere there are a large number of healthy people on staff.)
A "practice run" would give you invaluable
experience and then you'll be ready for the real thing!