Cobblestone to build a small enclosure around your portal (Ghasts cannot break cobblestone), a pickaxe for the flammable dirt, and some ladders or dirt so you can climb to reach the lightstone. You may also wish to bring bow and arrows for the mobs, as you will only need to attack the ghasts.
Sounds good, save for the bow and arrows.
I haven't seen many spiders and I don't have enough string for it.
However I shall punch they're fire balls right back at them, like a badass.