Firstly really nice to hear that ur shifting here.
R u posted here or u r going to start some business here??
Secondly Jeep is not at all recommended for that route. My chacha had travel from zhob route 2 times on mehran and another chacha traveled in Alto one time.
So u can easily travel in car.
Thirdly safest route is again the Zhob route because the sibi area is quite dangerous nowadays.
The best way is again Zhob because if u travel from Loralai route the road condition is very bad.
So again my adivce will be Isl-Talakang-Mianwali-D.I khan-Zhob-Quetta.
If u wanna examine this route u can see my Topic Roadtrip Quetta to islamabad. Search my posts