i've done a lot of shark fishing off the beach. the larger the reel the more line it holds. i wouldn't go with anything smaller than a penn 9/0. the older ones with the chrome plated spools hold 1200 yds of 50# dacron, i think the newer ones hold less. a 12/0 will hold 1200 yds of 80# dacron. the down fall is you can't cast them, so you need an inflatable boat or kayak to take the baits out. i always paddled them out about 400 yards, but most of my fishing was done in North Carolina and Florida around panama city. even 400 yards out there was only 25-30 feet of water. where you are may get deep faster. i like a 7' or 8' rod for beach fishing. even dacron stretches some and you'll need the extra length to get a good hook set.
in my opinion rays are the best bait. i've never put a ray out and not had a run on it. on top of that they are tougher and the blue crabs don't seem to mess with them. i've never used mullet, but it's a good oily fish so it should work fine. when we couldn't get rays we used bonito a lot, but the crabs can pick an 8# bonito clean in about 4 hours. so be prepared to take multiple baits out. also i wouldn't put out more than one big rod for each person there. i'm not sure how talented you are, but i could never get the hang of fighting two monsters at the same time.
i always made my leaders 20 feet long, but i sometimes fished from the pier, and i needed to be able to clip a rope on the leader when i got the fish close. 15' is plenty, 300# stainless braided with two 16/0 hooks for big baits.
if you're casting baits your limited to smaller baits and shorter leaders, hope and pray he doesn't tail whip your line. wade out to the first sandbar and cast as far as you can then free spool walking back to the beach. mind you i've caught some pretty respectable fish between the beach and the first bar so don't dally too long there after dark.
if i was a little closer i'd go with you and bring all the tackle you need. you'd still have to paddle the baits out, i'm getting too old for that.
mark