RE: How much in 5 gallons?
It is a little late to worry about ingredient proportions or whether you have a "purist" chili. Don't let your detractors get you down. I am solidly in the purist camp but I do recognize regional differences. Go with what you feel comfortable with and what is recognized as "chili" in your region.
My advice at this point is to use varied ground chilis, paprika for color, molido for depth of flavor and cayenne for heat. Don't forget to use plenty of cumin for deep down flavor. Do your onions and garlic in beef tallow, it will add greatly to the flavor. Don't worry about it being too hot, the bite of cayenne pepper is greatly reduced by long slow cooking, which you should be doing.
An aside to my fellow "purists": Sirloin in chili? That ain't chili, that's a wretched mess! Sirloin is not chili meat, it is far too tender. Proper chili should be made with the leanest toughest meat you can find. I find flank steak the best. Use sirloin tallow for flavor but not the meat, save that for the grill. As far as "ain't no beans in chili" it really depends on the time period you are talking about. During the Great Depression even in Texas, the greatest Chili Queen Parlors featured more beans than meat in their chili, it was a matter of economics. This is also the same time period that crackers, pasta and rice were added to chili as stretchers.
Anyway Edge, I wish you the very best of luck and hope you win.