which one is best choice to farm since i cant buy p pots on ge for the mages

Well, since you can't buy pray pots, which are pretty valuable for fighting Spirit mages...Logic says Abyssal Whips

Alternatively, kill the Sara ones that are in combat by the main entrance - no need for pray pots then.

 

If you feel that you have to camp something, I would do Mages - but remember campers are a slayers worst enemy!!

Just train Slaya.

yeah i would do slayer right now if i could but no money for pots or uber gears atm still earning money from when i sold entire bank