I replied a few posts up with my pures setup. Heres my 70 def tanks gear
Head: Torags helm
Neck: Armadyl pendant
Weapon: rune cbow
Chest: zammy dhide
Sheild: obby sheild
Legs: torag legs
Boots: dragon (i wear climbers when getting there then swap)
Hands: sara dhide vambs
Ring: Life

Ammo: 1k+ mith bolts.
Im currently getting 4k kills (1100 when i posted this) and this is what i take.
Head: Dragon med
Neck: Armadyl pendant
Weapon: rune cbow
Chest: zammy dhide
Sheild: obby sheild
Legs: Dragon skirt
Boots: dragon (i wear climbers when getting there then swap)
Hands: sara dhide vambs
Ring: Life

Ammo: 10k mith bolts
You ask why dragon not barrows? barrows will break 3 times getting 4k killcount. Dragon was next best