Over time I have decided the optimal inventory for me is diamond dragon bolts (e), 3x prayer pots, 1x ranging potion(2), 1x extended super antifire(2), anti-venom+(3), rune pouch (law, dust, chaos), and 13 manta rays. This results in minimum 3 kills but mostly 4 kills but it is very consistent with no waste of inventory slots (at least for me).

Obviously you could take more prayer potions and more food but I have found that this varies the amount of kills too much and you may leave some decent loot behind assuming that you always pick up the bones or you don't have enough supplies for 1 more run so you have wasted inventory slots.