As Brandon mentioned, a lot has to do with location - 30 also sounds like a good number. Better to take more than regret taking too little.
I would be working out what kind of structure and depths you will be encountering prior so that i could prepare my lure bag accordingly. It goes without saying that you should have a good cross-section so that you can be prepared for anything.
Most guys are after trophy GTs - by far, most trophy fish are taken on big slow-worked bloopers. A majority of lures in my packing would be this but definately not limited to. Stickbaits are deadly but take a seat to a blooper for me.
You may also like to break up the number by what conditions they can handle in case you encounter varied weather and ocean conditions - cover all your bases.