If your MP/flame you got 2 options: 85F - 60I - 5M | 85F - 42I - 25M.
As lighting you have 3 options: 80L - 60I - 10M | 80L - 45I - 25M | 85L - 60I - 5M. (Doesnt matter if your MP or INT)
About skills..
Farming ones:
Staff & manes you only need those both,you can use deadly fire also(High far dmg).
PK:
Staff, deadly fire,igzination,incineration,and if you still need some fire thron,fire impact and pillar of fire. You can also use ignition.Why not manes? if your target is not moving, manes & staff is the way

.
About stats :
While using MP heros : 255 MP,rest HP like 157 if i am not wrong
At least i would not use INT heros with over 151 MP points.
So my suggestion in case you play as support is:
Heros INT : 175INT - 151 MP - 91STR(You can wear c.mace&t.shield) rest goes to HP.