I would think it would depend on what kind of event - 1000 dancing people vs a dinner for 1000...or is it a mix?
What level of music do they want overall? Is it one big room or several, and do they want music in other other areas or just one party location?
I would think a call to a sound company and let them do their thing - then you just show up and play. If this is the convention center in town it's all union - you pay to have them haul your gear, plug in your power, setup your booth.
A wedding venue here had a grand ballroom - 40 feet across and 100 some feet long, can be divided into two rooms, has 2 bars on opposite ends of the room. DJ sets up across the thin dimension about 1/3 of the way into the combined room. Could seat 600, been there for 350-400 people and the far end of the 'second' room is kinda quiet and feels left out of the doings. More sound on the floor won't help that much...so IMO a second set of speakers (just tops) over there would help - but they'd have to be wireless because cords would have to cross the main entrance, the front of the bar, access to the kitchen.
I"m top heavy and not all about that bass, as Meghan says. I bought out a guy that retired in 2006 and did only weddings, had but one sub, and matching a customized 15 year old sub isn't gonna be easy (custom build I suppose). Alternatively buying two (or more) matching powered subs won't be cheap - as in I can't make a business case for the expense/investment at this time.