Thirty inch tongs will be sufficient for most of the venomous snakes you will encounter. They are also handy for reaching the snakes which are a few feet above you on the rocks.
The hot dog tongs are cheap and effective for picking up small venomous snakes and nasty invertebrates, such as the giant centipedes and scorpions. They should be bent a bit on the ends so that the sides are flush with each other.
The hook is an extension pole which will extend to about 12 feet. It is converted from a golf ball retriever. It is handy for hooking the snakes which are high up on the rocks. Because the hook will rotate, it is not much good for hooking snakes on the ground.
Bags are a must, and jugs are handy. Make sure that you do not leave them in direct sunlight if they have animals in them, particularly the jugs. Even if the air conditioner is running, the interior temperature of a jug or jar can get quite high.

Repair equipment can come in handy for repairing burned out bulbs or broken cords and wires. Sometimes it will be necessary to make splices. Joiners and electrical tape are not expensive, and can save a night.
Mesquite and acacia thorns, as well as sharp rocks, have flattened many tires in west Texas. Make sure you have a good spare tire. A plugging kit has saved me on several occasions. Just plug the hole and then re-inflate the tire with the portable compressor, which plugs into the cigarette lighter.
Duct tape can also be a handy thing to have. You can use it to make auto repairs, temporarily patch holes in bags, tape the lids on boxes, wrap the tops of bags and many other uses.
It is also not a bad ideal to carry a spare headlight or bulb. I have spent many hours repairing the failed equipment and flat tires of other herpers.