Help me choose new build

Can someone experienced help me decide which build make when Legacy league begins...
I watch some movies on YT and I liked 3 builds:

1.Necromancer witch(5 spectres)
2.Duelist Infernal Blow
3.8-10 Siege Balista build with Iron Commander propably Ranger( I think about Ice shots or cold skills with high freeze chance or some spells)

Conditions build must meet:
-not too expensive
-allow below 90lvl killing any boss in game easily
-allow relatively early in game around lvl 70 killing everything easily except hardest bosses
-fast cleaning high tier maps

Can somene tell me which of those builds meet my conditions and also tell me something about those builds ?

For now my favorite for next build is siege balllistas one...How it looks in practice(mean gameplay),this build has good dps? I need to know pros and cons of all 3 builds...

Necro is good after 90lvl but leveling it is a nightmare. Spectres dying so often so you waste lots of time going back for new spectres. I like necro builds because later on its just all about runnning while minions do everything. I just wish someone could make a valid zombie build. No spectres, just zombies.

8 totems takes too much time to place them all. Classic dual totem or 3/4 is better

Thanks for answer but I expect more answers from PPL.
So maybe someone suggest me other build this time(this will be my second league) which allow me to get all 3 league rewards from challenges this time?

Condinditions he must meet:
Very good dps
Medium or higher survivality
Fast map cleaning
Not too expenssive
Allow me to get all 3 rewards from upcoming legacy league relatively easily(I mean all challenges about killing endgame bosses solo without problems even without crazy gear).

I dont have time to watching tons of movies,analyzing equipment and gear right now so I will be appreciate if someone experienced who try many builds can suggest something really good which let me complete anything I want in upcoming league...As I read portal effect is 3rd reward so I want evade mistake I make in current season where I mess up my first char in this game then I maked second tanky one without dps and finally start third one- good one finally but because loosing lots of time for 2 previously characters I dont have now time to get 3rd league reward...

Maybe tomorrow, devs are getting ready to announce significant balance changes for 2.6 so we're waiting for that.

I have a 5 Spectre necro and honesty I had no issues at all leveling, in fact I thought the necro might have been the easiest char to level and I have a lot of chars. Just make sure you grab all the minion nodes first then u can go in for defense and survivability. The necro is a great, and easy, class to play. It can actually get pretty boring after a while.