Swamp trident, blowpipe+ addy darts, occult necklace are the mininum you'll want if you plan to farm zulrah. Barrows gloves, mage arena 2 cape and Ava's assembler, in that order, are optional but highly recommended.
Get book of darkness if you can afford. Blessed dhide is better than void, but it is easier to switch with void. 8 way with dhide, 4-6 way with void.
Darkbow/heavy ballista is good for last hits on mage phases if you can time it, don't bother if you can't.
I wouldn't bring ring switches personally, and of course don't forget your recoil(s) or you probably won't get 1 kill.
Vengeance is ideal, but you don't have the magic level, so use vulnerability with the runes in a rune pouch instead.
Do bring range pot mix, I wouldn't bring mage pot. At most use a divine mage pot at bank before going, or a mage pot mix if you're going to bring one in inventory. I would angler at bank before going, your stats will need help at zulrah