What should I bring with me to the Nether [Minecraft]?

I found the stronghold in my survival world, but realized I kind of needed blaze powder. I have a nether portal set up and ready to go, but I don't know what I need to survive. Besides the basics (torches, food, wood, etc) what should I bring with me to stay safe?

Bow and Arrows, to deal with Blazes and Ghasts that will often fly out of reach.
Snowballs also work nicely to injure Blazes and are more rapid-fire than a bow.

Cobblestone to build bridges over lava, or build a ramp/staircase/pillar up to a Nether Fortress (also so you can build a shelter that won't be destroyed by a Ghast's fireballs)
Gravel or sand to let you descend long drops safely

Flint and Steel, to reignite your portal in case a Ghast's fireball hits it and disables it.
Obsidian if you want build a portal close to a Nether Fortress for easier access to Blazes or Wither Skeletons.