Reply to How many watts do I need? 500 people party?

Sorry if this is a repeat question -

I'm dj'ing at a Wedding + Reception with 500 people in June. Wondering how many watt spears I'll need for the event.?

I'm renting speakers from another DJ cause the party is on the other side of the country. He's got the following:
(2) 800 watt Alto Speakers
(2) 400 watt JBL Speakerrs
(2) 400 watt Mackie Speakers

How much of that do I need? Do I need everything? Do I need everything plus more?

Confused - never dj'd a party this big.

Suraj