Hosting a party for 40 people

Hey, I am going to be hosting a party and would like to know how much alcohol I need to stock!

People will be paying some amount of money to help cover costs so a BYOB is not necessary,

I will be expecting 40, amongst 20 are heavy drinkers(shots, hard liquor, cocktails and more)

The rest either doesn’t drink, or is fine with sipping on a drink for quite some time, but are open to all drinks.

The party will last for 6 hours, and not everyone will stay until the end, so half at most will be left.

How much would I need to get to satisfy these demands? I would like there to be 2 cocktails that I’ll ready pre-made, cider, beer, wine, mix, shot material and liquor

Thanks!