Maxed 60 Def Pures can be pretty effective... At this level, you fight low-level mains (easy fights), but there aren't many creative tanks that can attack you. Your only real opponent would probably be a maxed ranged tank.. 99 range, 99 def. Just make sure you drink Antifires and it'd be a good account.
Well, it depends on how good pker you are. at 60 def, you will be forced to wear rune armour because dragons protects over everything. This translating to you getting smashed by zerkers. If you are a good pker and can use barrows without losing too much, then you have a chance against zerkers.
Zerkers owns mains in rune armour, mains with piety own zerker in barrows.