Well, if you get good gear then you don't need any points into mana.
For starters you only need enough str for all your gear, the same for dex. Since you aren't melee you really dont need max block. If you are going to wear things like occy, shako, sojs then don't put any to mana, and just pump up your life with vit. But if you don't have these items then add some to mana. My sorc which is a blizz sorc and does 3.2k damage has these stats and can kill pindle.
str-159- prolly way higher than i needed
dex-80
vit-290
eng-70
It gives me like 330 mana and about 750 life when my gear is added to it. Btw my gear is shity, trust me. Hope this helps in someway.