When making any sauce with meat you generally go four ounces per guest. So lets see, 4 times 300 will give you 1200 divide by 16 ounces, and you need 75 lbs. Cooking in batches of 25 lbs. On a commercial grill should work well, and then just transfer 25lbs. To three different pots. This in all should work just fine. You will need half as much sauce, so 2 ounces times 300 will give you 600 divided by 16 ounces, and you need 37.5 lbs of sauce or 18.75 quarts.