You need 4 Stamina Tablets. Last I checked though you don't need 80 Mega Phoenix to make Auto-Phoenix: Only 20. If you needed 80 I'd still be working on that thing!
I accidentely lied about how much gil I have though. I was looking at my new file when I posted that and when I went into my old one I discovered that I had 2.9 million. I've been working on it for the last week and a half and now I have about 10 or 11 million.
I managed to get enough armor to make the ultimate armor for everyone by fighting Varuna in Monster Arena. Did you know that with Rikku's Gillinoir ability on the Godhand you can actually make a 1000 gil profit from doing that? I found it interesting.
You can also make gil by fighting One Eye and selling the weapons he drops. A triple Ap weapon with one spare slot is worth 22,000 and a triple Ap weapon with two spare slots is worth about 65,000. It only costs 8,000 to fight him, and he'll always drop something.
Keep a two slot triple Ap weapon for your weakest character and customize it with Overdrive