I agree 100% with fishizzle.
I also have to add that you are riding in someone elses high priced bass rig. Keep your stuff organized! Don't leave garbage in his boat. When your done with your drink bottle put it into your bag.
Keep your gear ready to stow at a moments notice. When the owner is ready to hit a new spot, he'll start strapping down his rods and by the time he has, you should be about ready to go. Basically don't make him wait for you.
I find it best to take out the lure I want and then place the box back into my bag. That way you don't create clutter.
Don't cast over the center line unless they say it's ok. Kind of like in Ultimate match fishing.
Make sure you have rain gear. If you can't get goretex, get something cheap untill you can get goretex. If your riding in a boat with a motor bigger than 150 HP and your wearing plastic raingear, it's gonna rip right off your body.
When I fish a tournament here is what I take......
fishing bag with 5-8 boxes
5-9 rods rigged and ready to go. Rig them at the ramp if need be.
duffle bag with rain gear, snacks and a sandwich along with a couple drinks or more depending on the temp.
I usually buy more snacks than I eat on the water, that way I have some grub for the way home.
You might be wise to take a pair of sandles too.
You say he like to sit and soak. Make sure you have some finesse lures. Stuff like tubes, worms, etc.... If I was you, I'd start off throwing search baits. Then once the bite slows or you dont catch any, switch to worms, tubes, and similar plastics.
Post where you'll be fishing....maybe someone can give you some good lure colors to use.