can't decide which class to pick for my frostbolt build

hi all!
for 3.0 i wanted to play a frostbolt miner, but after the change of arcane surge that made it not work anymore with detonate mine i've decided to go self cast.
the problem is that i can't pick the class for the build...
would you guys help me make up my mind?

this is a link to a pastebin with the pob build.

it has all of the versions i've made, which are:

-ASC (ELE/ASS) - mom/181% life
-ASC (ELE/ASS) - mom/phase acro/152% life
-ELE - mom/phase acro/152% life
-ASS - mom/phase acro/152% life

which one would you choose? and why?
also: do you think that for the build there are better subclass for scion instead of assassin?