Idt CA Final Query

I've already posted a query regarding Manoj Batra Sir's book.
I have a consideration in this regard. I see it to be too huge to complete before may 2018 - approx 1100 pages, if I'm not wrong.
I believe, there is not much time left, with 8 subs in hand. I can max spend 7 to 9 days for idt. Else, my revision will get affected.
What about other authors?
I know Bangar is reputed. I wanna know one thing.. I have already appeared more than once in old Service Tax regime. So, if I take up Bangar's Summary compiler, will I be able to follow gst and score good or decent marks? Pls suggest. Thanks.