I have the Tilos bag - it folds up into it's own pocket for transport. And holds everything I dive with. Get one with backpack straps.
Amazon.com : Tilos Mesh Backpack Bag for Scuba Diving, Snorkeling, and More, black : Sports & Outdoors Some of the Stahlsac's come with a dry pocket - wish I had one. The bag is stowed under your seat so your gear drips on it.
If you dive in the Caribbean gloves are illegal in the marine parks because wearing gloves encourages touching coral. So IMO $20 3MM gloves work fine. If your plan is to wreck dive, you'll want good gloves. Of course in cold water you'll need the appropriate thickness gloves. I don't even know where my gloves are.
Cutting device - get two. Trilobyte's are nice but only handle situations where you can get the line in the throat. Back it up with surgical shears or a good knife. You can't generate enough force with a Trilobyte to cut some solid steel leaders etc. Even cheap shears cut thicker metal - I've seen a penny cut in half. Only buy shears with stainless steel pivot screws - cheaper ones rust out in a year. I also have a sweet Titanium 4" blunt nose knife. Mounted on one side of my BC - the shears on the other. Never know which hand you'll be using to cut yourself free.
Unless you're going to local dive (or drive to the ocean) with
your tanks there's no reason to buy weight. In 33 years I have never been anywhere it wasn't provided as part of the tank rental. Except maybe SoCal because some boats there don't provide tanks either. I dive warm water, AL-80's (standard resort tank) with my weight integrated BC with no control problems. I shoot video so I really have to be able to hold in the water column. My BC has rear trim pockets - I find 70/30 weight split is optimal, 60/40 I can live with.
If you're going to buy a light, I'm having really good luck with the Cree Led's - the name of the techology, not a brand. They're bright, white light.
You might look at spring straps for your fins also - good ones go in the $30-50 range. And you never have to worry about breaking one again.
Get a backup mask also. They're cheap insurance when you lose/drop yours. Or someone drops a tank on it. I bought a $25 Sherwood advertised as a soft skirt - it's soft enough to fold it and stick in a BC pocket. Not to be confused with $100 Frameless masks.
My concern with the Dive Caddy is not that it will hold all my gear. My concern is that with 25" long fins, there's no way it will fit into the 22" sizing box at the gate. United just started enforcing 22x14x9 (the industry standard) in some airports. So if they take your Dive Caddy and gate check it, I'd worry about my gear being protected. I've had my legal carry-on roller taken when the plane was full - at my destination I didn't recover it at the gate, it went thru the baggage system.
